A number of people detained in raids on Wednesday were listed as “prohibited” contacts on the control order of a suspect in a separate counter-terrorism investigation, NSW police have confirmed, amid questions over why 15-year-old Farhad Jabar was not on the radar of counter-terrorism police.

The joint counter-terrorism team executed search warrants on Wednesday and detained four people in relation to their investigation into the fatal shooting of 58-year-old Curtis Cheng by Jabar outside the NSW police state crime command on Friday.

Deputy commissioner Catherine Burn said at a press conference on Wednesday that the men were detained because police suspected they may have some information of the events.

Burn initially told reporters that none of the people detained were listed as restricted persons on control orders. A spokeswoman for NSW police later said Burn had misheard the question.

It is now evident that at least three of the people detained are listed on a control order that was recently sought by the Australian federal police. That control order is now facing a constitutional challenge.

Being listed as a prohibited contact places no legal obligations on the person who is listed. But the subject of the control order is not legally permitted to contact the person unless they are authorised to.

Control orders are anti-terrorism powers that allow police to apply to restrict a person’s movement and associations. Four control orders have now been sought by the Australian federal police and are currently being considered by the federal court.

Burn faced questioning during the press conference about the police’s lack of information about Farhad before the attack.

She responded: “It’s a reality of life, we can’t be everywhere, with everybody at every single second of the day … we are doing everything we can, based on the information and evidence we have.”

Three of the four people detained in Wednesday’s raids were released without charge, according to the Australian.

More than 200 armed officers raided homes in Guilford, Wentworthville, Merrylands and Marsfield at 6am on Wednesday, arresting the four men aged between 16 and 22. They are suspected of having some knowledge about the fatal shooting of NSW police employee Curtis Cheng.

They included past and present students of Arthur Phillip high school, the school attended by Jabar. The 16-year-old was in his same year.

NSW police deputy commissioner Catherine Burn says authorities suspect those arrested have some knowledge of Friday’s shooting and could have influenced Jabar.

Investigations into Jabar’s motivation continue but Burn said it’s suspected “there was some influence” that was either of an ideological, religious or political nature.

Police have not confirmed reports the gun used by Jabar came from a Middle Eastern crime figure.