A Bellport man was arrested Tuesday night after undercover officers responded to his online advertisement of heroin for sale, Nassau County police said.

Obadiah Y. Johnson, 28, of 130 New Jersey Ave., was arrested at 8:50 p.m. after detectives from the Nassau County police Narcotics/Vice Bureau conducted an undercover operation in conjunction with Garden City police detectives, a news release said.

Police said undercover officers responded to Johnson’s advertisement on Backpage.com, claiming they were interested in purchasing the heroin he had listed for sale. Detectives then arranged Johnson at a predetermined location on Sunnyside Boulevard in Plainview.

When Johnson showed up, cops arrested him and found twenty bags of heroin and an undetermined amount of cash.

Johnson was charged with third-degree criminal sale of a controlled substance and third-degree criminal possession of a controlled substance. He was arraigned Wednesday at First District Court in Hempstead and is currently being held in lieu of $10,000 bail, according to court records. Johnson is due back in court on Friday.