Yassin Nassari, a Category A prisoner, was sentenced to 3 1/2 years in prison last summer after being convicted of trying to smuggle blueprints into Britain showing how to build a missile.

He was released early from Wakefield prison last month, the Ministry of Justice confirmed Friday.

The move is believed to be the first time that a convicted terrorist has been released under the plan, The Times of London said.

It was also seen as surprising because Nassari allegedly was moved from Belmarsh prison in South London amid fears that he planned to blow it up, The Times said.