British prosecutors drop terrorism case against former Guantanamo Bay detainee Moazzam Begg

British prosecutors dropped terrorism charges Wednesday against a former Guantanamo Bay detainee who is a high-profile advocate for the rights of terror suspects.

Moazzam Begg had been due to stand trial next week on seven counts relating to the war in Syria. But in a last-minute reversal, prosecutors acknowledged that new evidence had emerged that undermined the case.

"The prosecution ... after careful and anxious consideration, have reached the conclusion that there is no longer a realistic prospect of conviction in this case," prosecutor Christopher Hehir said.

A judge at London's Central Criminal Court then acquitted Begg of all charges. He is due to be freed later Wednesday.

Begg has been in prison for seven months awaiting trial. He had been due to go on trial next week accused of attending a terrorism training camp in Syria in 2012-2013 and of funding terrorism, among other charges.

Begg, who lives in Birmingham, was arrested in Pakistan in 2002 as an "enemy combatant." He was held by U.S. forces in Afghanistan and sent a year later to the U.S.-run prison camp in Cuba. He was released without charge in 2005.

He is the outreach director for the campaign group Cage, wrote a book about his Guantanamo experiences and has been active in challenging the conduct of Western governments in fighting terror.

Begg's attorney, Ben Emmerson, told the court that his client's stance on Syria was not unlike that of the British government.

"Mr Begg did not train anyone for the purposes of terrorism as defined in the 2001 act," he said. "Mr Begg says he was involved in training young men to defend civilians against war crimes by the Assad regime."

The West Midlands police issued a statement defending the investigation and said that authorities continually "assess the evidence in terrorism prosecutions and will alter course if that is the right and proper thing to do.