By Kristina Wong - 08/19/14 10:31 AM EDT
The Army announced Tuesday it is extending its investigation into Sgt. Bowe Bergdahl, a former prisoner of war in Afghanistan, through September.
Since his return in May, Bergdahl has been the subject of an investigation regarding the circumstances of his disappearance from his post, leading to his capture by the Taliban in 2009.
Although the investigation is fact-finding and not criminal in nature, it could lead to criminal charges, and force Bergdahl to pay back wages earned during his captivity.
The investigating officer, Army Maj. Gen. Kenneth Dahl, interviewed Bergdahl for the first time after a recovery phase two weeks ago.
Bergdahl's lawyer, Eugene Fidell, said the 28-year-old sergeant was cooperative.
The investigation was due to wrap up 60 days after Dahl’s appointment in mid-June, but Dahl has asked for more time to complete his report.
He may also interview more witnesses, the Army said.
"Army senior leaders have been advised of the status of the investigation, and Maj. Gen. Dahl expects to submit his report for review in September 2014,” the Army said in a statement.
Bergdahl was released in May after the Obama administration exchanged five Taliban commanders at the Guantánamo Bay detention facility.
The prisoner exchange stroked ire from a Congress that was not notified 30 days in advance as required, as well as national security concerns about the prisoners returning to the battlefield.
Some lawmakers also said that the administration negotiated with terrorists against U.S. policy, since Bergdahl is believed to have been held by the Haqqani Network, deemed a terrorist group affiliated with the Taliban in Afghanistan.
If Bergdahl is found to have deserted, or been absent without leave, it could lead to criticism that the administration released senior level Taliban members even as U.S. troops are expected to continue an advising and counterterrorism mission in Afghanistan.
Under terms of the release, the five senior Taliban will spend one year in Qatar.