He played the role of Marcus Licinius Crassus in Spartacus: War of the Damned and also had roles on television in London's Burning and Family Affairs.
Some of his earlier acting work was in the theatre. He played roles in adaptations of On the Waterfront and Much Ado About Nothing.
Notable films roles of his include a leading part in the 2009 film Invisible Eyes and the part of Ben Talbot in the 2010 film The Wolfman.
His brother is actor Jason Merrells.
He played detective Philip Marlowe in a stage adaptation of Raymond Chandler's novel The Big Sleep.