The Islamic State group has released a video showing a British man who identifies himself as a journalist and says he is a prisoner of the extremists.

In a slick video shot with three cameras, the man identifies himself as John Cantlie, a photojournalist who worked for publications including The Sunday Times, The Sun and The Sunday Telegraph.

He says he came to Syria in November 2012 and was subsequently captured by the Islamic State group.

The group has beheaded two U.S. journalists and a British aid worker, and threatened to kill another British hostage. Cantlie's name has not been mentioned among foreign hostages held by the group before, apparently because of a media blackout.

The British government declined to comment on the video.