One of the five prisoners exchanged for Army Sgt. Bowe Bergdahl in May 2014, is reportedly being investigated for making suspicious phone calls to Afghanistan over the past few months.

According to CNN, this is the first known time one of the five detainees who were released has been suspected of attempted to make contact with any militant groups in the Middle East, but this one instance has raised the question of whether the other four will follow suit.

All five former detainees are said to be in Qatar, where their communications have been monitored by a U.S. intelligence program for months. The program in question is saying they have evidence showing the former detainee in question had “reached out” to militant groups and encouraged further militant activity.

However, one official told NBC News the former detainee had called family members in Afghanistan and there is no evidence showing the phone calls were to members of any militant group in the area. This official also added the content of the phone calls contained no “threatening activity or planning.”

No matter what the content of the suspected phone calls, the governments of Qatar and the U.S. are working together on this new issue.

Rear Admiral John Kirby had an interview on the show ‘Erin Burnett Out Front,’ where he said, “We have a strong security partnership with Qatar, and are in constant dialogue with Qatari government officials about these five detainees and we are confident that we would be able to mitigate any threat of re-engagement by any of these members.”

The Pentagon released a statement saying they would not comment on cases involving the detainees. The statement also said, according to the Daily Mail, “we take any incidence of re-engagement very seriously, and we work in close coordination through military, intelligence, law enforcement and diplomatic channels to mitigate re-engagement and to take follow-on action when necessary.”