A young U.S. serviceman on trial for leaking confidential and top-secret defense documents — specifically about the war in Ukraine — to an online forum pleaded not guilty Wednesday.

Jack Teixeira, 21, of the Air National Guard (USANG), was arrested by the FBI in April.

He was stationed at Cape Cod, near Boston, and was an IT and dispatcher. He is accused of releasing classified documents on the social networking and discussion site Discord, from where they made their way to other social networking sites, causing a huge uproar.

He faces six counts of possession and transmission of information related to national defense. Each of them carries a sentence of up to 10 years in prison, in other words, summarizes an NBC News report, he could face up to 60 years in prison and a fine of up to 1.5 million dollars.

The young man was brought before a judge in Worcester, Massachusetts, on Wednesday. He pleaded not guilty, according to documents.

The defense attorney requested that he be temporarily released pending trial. The headquarters rejected the request.

Images of the young man’s arrest by police outside his family home have gone viral, days after a series of leaks in the US press.

The leaked documents revealed, among other things, US intelligence concerns about the viability of the Ukrainian counteroffensive to recapture territory from Russian troops. They also suggested that Washington spies on some of its closest allies, notably Israel and South Korea.

The case has embarrassed the US government and raised questions about security gaps. The young man held a top-secret clearance, which allowed him access to extremely sensitive material, despite his low rank.