He is known for his roles as journalist Simon Kitson in ITV's drama The Bill, as Ben Harding in the BBC One drama Casualty and for his recurring role as DS Kevin Geoffries in Wire in the Blood.
He has appeared in many television dramas, including Wire in the Blood, The Bill, Silent Witness, Casualty, Holby City, Waking The Dead, Heartbeat and A Touch of Frost.
He played Jamie in the world premiere of Jonathan Harvey's Beautiful Thing, starred in Mark Healey's adaptation of John Fowles' The Collector, and toured the US with the Royal Shakespeare Company, as Francis Flute in A Midsummer Night's Dream.
[2] In 2014, he appeared in Lotty's War (written by Giuliano Crispini and directed by Bruce Guthrie) at the Yvonne Arnaud Theatre, Guildford, before it began touring the UK.
[3][4] Letheren previously lived in Bristol with his long-term partner, actress Georgia Taylor, whom he met on the set of the television series Casualty.