Several finance websites — including Forbes.com and Seeking Alpha — have published articles by guest contributors who were allegedly paid to promote the stocks they were writing about, raising ethical concerns.

FORTUNE — Stock promoters have a new way to play the new media game.

In the past year or so, several finance websites — including Forbes.com, Seeking Alpha, Wall St. Cheat Sheet, and others — have published articles by authors who were allegedly paid to promote the stocks they were writing about. These articles were not labeled as advertisements and carried no disclosures that the authors had been compensated by their subjects. In fact, on at least one of the websites — stock blog Seeking Alpha — the articles carried a disclosure stating the author had not received any compensation from anyone outside of Seeking Alpha to write the article. Seeking Alpha now admits that some of those disclosures were inaccurate.

The articles in question were published through the websites’ contributor networks and were allegedly paid for by an investor relations firm called The DreamTeam Group. Most of these pieces focused on so-called penny stocks — companies with shares that trade for less than a dollar and not very often, a favored terrain of stock promotion schemes.

While not all of the facts are clear, the websites admit that they were duped. In the past few weeks, more than 100 articles have been pulled from Seeking Alpha, Wall St. Cheat Sheet, and other websites that have been caught up in the stock promotion scheme.

In some cases, the stock promoters were successful. In late December, Forbes.com published an article by Tom Meyer called “The race to develop a brain cancer treatment takes an interesting turn.” The article said a small biotech company called CytRx had “remarkable results” in a recent drug trial and “appears poised for a significant run in the months and years ahead as the company’s platform continues to be validated by science.”

Within days of the article’s publication, CytRx’s stock rose nearly 50% to $6.90. Last week, a class action suit was filed against CytRx, its CEO Steven Kriegsman, and an investor relations firm The DreamTeam Group. The suit says that CytRx (CYTR), through DreamTeam, hired Meyer and another author named John Mylant to place positive articles about the company and its shares on Forbes.com and other websites. According to the suit, the articles did not indicate that they were written by paid promoters or that Meyer and Mylant had a business relationship with CytRx. CytRx declined to comment.

Meyer’s article on CytRx no longer appears on Forbes.com. It’s unclear when it was taken down. A previously functional link to the story goes to a Forbes.com error message that says, “We can’t find the page you requested.” Meyer does have a contributor page on Forbes.com, but there are no articles listed on it. Meyer’s contributor bio says he is an “options volatility trader focused on the healthcare industry” and that he has worked in investment research, but there is no mention of DreamTeam or that Meyer has ever worked for an investor relations firm or as a paid writer.

Mia Carbonell, a spokesperson for Forbes, says that Meyer’s articles have been removed from Forbes.com and that Meyer is no longer a contributor to the site. “After careful consideration, we determined that the content did not meet Forbes’ editorial guidelines.”

DreamTeam, which appears to be tied to many of the articles now being removed several financial new websites, did not respond to a request for comment. (More on them later.)

A slippery slope

In the last few years, a number of financial news websites have been rushing to publish articles written by non-journalist guest contributors as a means to expand coverage and web traffic. The idea is that if you open up the world of journalism to people with experience and a stake in financial markets, you will get better information. But also important to these sites, perhaps more so, is that the contributor content comes at no or little cost. To get around conflicts of interest, the sites have relied on disclosure policies. 

(Full disclosure: Fortune.com, which is a competitor to Forbes.com, Seeking Alpha, and the other financial websites listed in this article, allows its contributors to own shares of the companies they write about, as long as that stock ownership is disclosed. All contributor articles are edited by Fortune.com staff.)

But a system based on disclosure alone doesn’t seem to be enough.

Enter Richard Pearson, an investor who has written an expose on DreamTeam and its ties to articles about CytRx and other companies on media websites. He says he believes the promotional articles began to surface about a year ago, but they have been multiplying in the past few months. And he says he has evidence that other investor relations firms or stock promoters are also using financial websites to pump shares. “I don’t think it’s a lot of articles relative to the total on these websites,” says Pearson. “But relative to what it should be, which is zero, it’s a lot.”

Pearson himself is very much a part of this opaque corner of the news world. He is a regular contributor to Seeking Alpha, one of nearly 9,000 such contributors. He often writes negative articles about smaller companies, many of which he has shorted, or bet against.

In early January, Adam Feuerstein, a reporter at website TheStreet.com noticed five very similar articles on Seeking Alpha, all recommending shares of the same small company, Galena Biopharma (GALE). The articles carried one of three different pseudonyms but appeared to be written by the same person. After Feuerstein sounded the alarm, Seeking Alpha quickly took the articles off its website. About a month later, Feuerstein reported that at least some of the articles appeared to be commissioned by Galena through a deal with DreamTeam, which the company had hired to promote its stock. On Tuesday, Galena announced that the Securities and Exchange Commission was investigating its relationship with an investor relations firm. Galena declined to comment.

TheStreet, which has its own contributor network, also has published articles that appear to be written by DreamTeam’s stock promoters. TheStreet has since removed articles by Meyer and Mylant, the two authors named in the CytRx suit. Meyer had a contributor page on TheStreet.com (which was removed from the site after Fortune.com contacted TheStreet looking for comment) that made no mention of his ties to DreamTeam or any of the companies he has written about.

“To our knowledge, Adam Feuerstein’s reporting on this story was the first to come out,” says William Inman, who is TheStreet’s editor-in-chief. “TheStreet has a rigorous system of protections in place for outside contributors.” Inman says that contributors must sign a code of conduct and that all articles published by the site are edited by TheStreet staffers. Inman says Tom Meyer tried to publish another article on TheStreet under a woman’s name. That article was never published. Meyer did not return calls for comment.

For its part, Seeking Alpha published Pearson’s detailed article on CytRx’s alleged stock fraud and its ties to The DreamTeam Group. At the same time, the site pulled 18 articles that appear to have been missioned by DreamTeam on behalf of its clients. Nevertheless, other articles that seem to be the work of the firm are still up on the site.

For example, Seeking Alpha has an article by Mylant, touting ForceField Energy (FNRG). Mylant’s disclosure in the article says he did not receive any compensation to write the piece. Yet ForceField is listed as a client on DreamTeam’s website. Seeking Alpha, which is in the process of reviewing and removing other articles, says it has evidence that Mylant was paid by some of his subjects to write articles about them. Mylant could not be reached for comment. ForceField Energy did not return a call for comment.

Pearson’s role in this matter is not free from conflicts. He says that he was contacted by Meyer to write positive articles on CytRx and other clients of DreamTeam, which he claims he never did. That doesn’t appear to be the case, though. In late January, TheStreet published an article by Pearson titled “3 Oncology Biotechs to Watch.” Both CytRx and Galena are highlighted in the article. Pearson says he wrote the article independently of DreamTeam, even though it was after he was contacted by Meyer to write about those companies. He says he was not paid for writing TheStreet article, and that it was clear that he was not recommending that readers buy either CytRx or Galena shares. Pearson says he did not have investments in the stocks at the time the article was published.

But Pearson did take a short position in CytRx shortly before submitting his expose on the company and its ties to DreamTeam to Seeking Alpha, meaning he stood to benefit from the negative press he was creating. To be sure, at the top of Pearson’s article is a disclosure that admits he had shorted CytRx stock.

On Tuesday, The New York Times reported that Seeking Alpha is being sued by hedge fund manager David Einhorn to determine the real name of one of the site’s pseudonymous contributors.

Seeking Alpha managing editor George Moriarty says the site takes a number of steps to vet its authors. He says all Seeking Alpha contributors provide the site with their names and contact information, even if they end up posting under a pseudonym. He also says that the site does not allow authors to use multiple pseudonyms and requires authors to disclose any conflicts of interest on every article they publish on the site, including whether they own the company’s shares, have bet against them, or if they have received any other compensation for “writing those pieces. Articles are taken down when there is “clear evidence” that authors have violated the site’s terms of use.

Wall St. Cheat Sheet, another financial news site, has removed about 100 articles from its website in the past two weeks that were written by individuals with ties to DreamTeam. Wall St. Cheat Sheet CEO Damien Hoffman says that contributor content has accounted for about 1% of the total articles on his site. The rest are written and produced by its 65-member staff. The site is also no longer publishing contributor content.

Hoffman says that Wall St. Cheat Sheet launched its contributor network last fall as a means to add lower cost content and that authors were vetted mostly based on the quality of their writing. Eventually, Wall St. Cheat Sheet cleared 12 outside writers to be part of its contributor network. Four of those authors, it turns out, have had ties to DreamTeam. After being contacted by Pearson in early March, Hoffman says his site pulled all of the articles written by those authors, even if they weren’t on companies that were known DreamTeam clients.

Hoffman says stock promoters are just one example of a “systemic problem” of conflicts in financial media in general, explaining that news sites that rely heavily on contributor content are particularly at risk of running problems. “I have the utmost respect for Seeking Alpha, TheStreet, The Motley Fool, and others,” says Hoffman. “But I think the model is broken. Not sure how the crowdsourced contributor content model can be policed.”

What’s behind the curtain?

DreamTeam’s website says its “objective is to create and execute a customized strategy that produces measurable results and attracts a wider following of investors to improve each client’s overall market valuation.” The company runs a series of websites, including Home Run Stocks, got stock tips?, and QualityStocks, which publish articles or produce newsletters on publicly traded companies. These websites do say that much of the content on the websites has been paid for by DreamTeam clients. And DreamTeam includes a list of its clients and what it has been paid for the work. The fees range from $15,000 to nearly $605,000.

DreamTeam is run by Michael McCarthy and is based in Indianapolis, Ind. McCarthy’s bio says he has a background in brand development and has worked at companies like Xerox, Best Buy, and Cellular One. McCarthy did not return phone calls requesting comment about his company.

According to its website, DreamTeam says it has “carefully assembled” a team of over 70 professionals. Its “Meet Our Team” page does have dozens of avatars next to employee bios, but most of the staffers are only listed by their first names. The bulk of the employees are listed as journalists. Tom Meyer, the apparent author of many of the articles in question, is not listed among the company’s employees.

Ted Haberfield, whose investor relations firm MZ Group formed a partnership with DreamTeam two years ago, says that DreamTeam hires outside writers to post stories on financial websites like Seeking Alpha and others. Since engaging with DreamTeam, he says he has outsourced some work to the company, but he says that his company does not directly compensate writers to post stories on websites. He declined to say what work he had outsourced to DreamTeam or what clients he had referred to the firm.

Besides McCarthy, only three other employees are listed by their full names. One, Jenn Hoffman, is a reality television star who appeared on “The Apprentice” in 2007. Hoffman says she did some work for DreamTeam on and off for a few years, hosting web videos and some events, and it has been a few years since she has had any contact with the company. Vanessa Ramirez, who appeared on reality shows “America’s Next Top Model” and “Love in the Wild,” is also listed as a DreamTeam employee. Ramirez did not respond to a request for comment.

Back at Seeking Alpha, the reaction to Pearson’s expose of DreamTeam’s work, which has received over 400 comments, has been decidedly mixed. A number of commenters praised Pearson’s work. But many have questioned his motives for writing the relatively positive late January TheStreet article on CytRx before eventually shorting it. Had he actually been pumping the company’s shares just to sell them off? Others said the fact that he stood to benefit from his negative article made him no better than the IR firm he was claiming to expose. There has been almost no criticism of Seeking Alpha itself.

“I don’t like journalism entities that allow people to write about stocks they own,” says Chris Roush, a senior associate dean at the University of North Carolina-Chapel Hill journalism school. “Disclosure helps, but you still wonder about the writer’s motives.”