A former Guantanamo Bay detainee who is a well-known advocate for the rights of terrorism suspects was arrested on suspicion of Syria-related terrorism offenses, British police said Tuesday.
West Midlands Police said Moazzam Begg was one of four people arrested in the Birmingham area of central England.
Police said Begg, 45, is suspected of "attending a terrorist training camp and facilitating terrorism overseas."
He was arrested along with a 44-year-old woman, her 20-year-old son and a 36-year-old man. Their names were not released.
Police in Britain do not usually name suspects until they are charged. The force said it was identifying Begg to the media "as a result of the anticipated high public interest."
The four suspects were being questioned at a Birmingham police station, while counterterrorism officers searched their homes.
Begg was held by the U.S. government at Bagram detention center in Afghanistan then Guantanamo Bay for nearly three years after being arrested in Pakistan in February 2002 on suspicions that he was a member of Al-Qaeda.
In 2005, Begg, along with the three other British citizens remaining at Gitmo, were released from the detention facility into the custody of UK officials. He and the other three detainees were questioned for a day by Metropolitan Police and then released without charge. After his release, Begg became a director of the advocacy group Cage, which campaigns against alleged abuses committed in the name of fighting terrorism. He is a well-known figure who appears frequently in British media.
Cage had no comment Tuesday.
Concern has been mounting in Britain over the number of UK nationals traveling to Syria to help rebels fight against the regime of President Bashar al-Assad. Police fear they may become radicalized or attend training camps run by hardline groups like Al-Qaeda before returning to the UK where they could pose a security risk.
British police have already arrested 16 people on suspicion of terrorism offenses related to Syria this year, some as young as 17, compared to 24 such arrests in all of 2013.
President Barack Obama said in January that 2014 should be the year to finally close down Guantanamo Bay, which has been widely condemned. Its remaining 155 prisoners were rounded up overseas after the Sept. 11, 2001, attacks on the United States and have been held without trial ever since.
Al Jazeera and wire services