Graham McTavish (born 1961) is a Scottish television actor. He has played the character Warden Ackerman in Red Dwarf in five episodes of series 8. McTavish has also had many supporting roles in British dramas and films such as Casualty, Jekyll, The Bill, Taggart and Sisterhood. He also played the ill-tempered Mercenary Commander Lewis in Rambo, had a role as Desmond's drill sergeant in the fourth season of Lost, starred in Ali G Indahouse as a Customs Officer and played a Russian pirate in NCIS. He played Ferguson in 4 episodes of season 4 of Prison Break. He has also starred in the film Green…