Idris Elba's toughest acting job was on 'Crimewatch'.

Idris Elba

Idris Elba

The 44-year-old star admitted it was hard having to consistently play real life violent criminals who had committed "gruesome" acts on the BBC show that reenacted crimes to help jog the public's memory and catch perpetrators.

Asked what his toughest acting gig was before finding fame in 'The Wire' he said: "'Crimewatch' reconstructions back in the day, they were tough. They were pretty gruesome.

"But in New York I had small parts in 'Law & Order' and did some theatre... each job was a blessing and took me a step closer to my dream."

Idris has just finished shooting Stephen King's 'The Dark Tower' in which he plays gunslinger Roland Deschain opposite Matthew McConaughey's Walter Paddick and was touched to get the iconic author's seal of approval for the role.

Asked if he'd ever met King, he said: "Only on Twitter, not in real life. Who meets anyone in real life these days? He sent me a message saying how happy he was that I was playing Roland, the hero of the books. He wished me luck and that was it. Matthew McConaughey plays the villain - he's great. Really intense, but nice. He plays a wacky character called The Man in Black.

Meanwhile, the 44-year-old actor was recently seen in 'Star Trek Beyond' playing Krall and admitted the experience felt like "torture" because he's "very claustrophobic" and hated wearing a prosthetic mask.

He told Shortlist magazine: "I used to watch it as a kid with my parents. When I got asked to be in it, I couldn't believe it.

"I was like, 'I'm going to be in a Star Trek film!' It was a greta experience, one of the hardest though, with all the prosthetic playing Krall. I'm very claustrophobic, so wearing a mask for 18 hours a day was torture."