A U.S. soldier has been detained on suspicion of leaking a classified combat video to WikiLeaks.

Army Specialist Bradley Manning, 22, is the prime suspect in a case that involves a video that was posted on the whistle blowing website, WikiLeaks. The video in question is footage of a 2007 helicopter attack in Baghdad that claimed the lives of many innocent civilians.

Manning was stationed at Baghdad’s Forward Operating Base Hammer when he was arrested two weeks ago. The arrest came about because of a tip from Adrian Lamo, a former computer hacker. Lamo told authorities that Manning had been bragging about leaking the footage to the site. According to Lamo, Manning has leaked more than 260,000 classified videos to WikiLeaks, including footage from another air strike in Garani, Afghanistan that involved civilians.

Lamo took to Twitter to explain the reasoning behind his decision to report Manning. He wrote that he reported Manning for fear that he was compromising national security. “I outed Manning as an alleged leaker out of duty. I would never out an Ordinary Decent Criminal. There’s a difference,” Lamo wrote.

The Pentagon has released the following statement:

“The Department of Defense takes the management of classified information very seriously because it affects our national security, the lives of our soldiers, and our operations abroad.”