A 25-year-old man arrested in a series of England anti-terror raids on Tuesday was tonight released without charge, a spokesman for Scotland Yard said.
The man, who was arrested in Lancashire, was released shortly before 9pm.
A police spokesman said: “The man received legal representation throughout his detention.
“At this stage it would be inappropriate to provide further details regarding the operation and the arrests.”
Police have been granted an extension to custody time limits, which allows them to hold the 11 remaining men, aged between 19 and 32, until Sunday evening.