Before actor Liam Thomas took to the stage, he spent a decade pretending to be other people working as an undercover police officer in Britain and Europe, keeping company with drug lords, arms dealers, and serious criminals.
As a teenager, he had always wanted to be an actor, but his father told him acting was not a proper job for a man.
His father was a policeman, and so, after a spell in the navy, Liam too joined the ranks of the police.
Liam was a rising star, and before he was 30 years old he had become a top detective in the Metropolitan Police.
It was then that he was approached to work undercover.
Covert policing has been under the spotlight recently in the UK after revelations that a Metropolitan Police Constable, Mark Kennedy, spent seven years infiltrating green campaigners only to then offer to give evidence in their defence at trial.
For Liam, after ten years of working undercover, in a role where he had to constantly deceive people, the pressures eventually became too great.
He suffered a mental breakdown and left the police on medical grounds in 2004.
Today he still takes on other peoples' personas, but working now as an actor, rather than an undercover policeman - most recently in a production of Macbeth.
Liam Thomas came into the Outlook studio and told Lucy Ash about his extraordinary double life.
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