"It’s not fun making Luther" says Idris Elba

In fact, he adds, "it’s depressing”.

The acclaimed BBC1 thriller will be back for four new episodes beginning on New Year's Day, with Elba back in the lead role as maverick cop DCI John Luther.

Elba admitted to RadioTimes.com that the tough nature of the drama makes filming the series a gruelling experience.

“It’s a tough show to make; it's not fun making Luther," the 46-year-old actor said. "It's very gruelling. Tough, long hours and obviously because of the nature of the type of show it is, it deals with murder, it's depressing if I'm honest. But it's a good bit of drama and the fans really love it.”

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Elba, who’s been playing Luther for eight years, added that the show is always filmed in the autumn and winter to avoid disrupting a “good time” in summer.

“We don't make Luther in the summer. We're on holiday having a good time, we don't want to make it then! You want to make it when it's cold; it sets the mood and the feeling for the type of show it is.”

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He does have a point. The new trailer for Luther, below, sees the detective tackling a whole medley of gruesome crimes in a chilling, fright-filled London.

https://www.youtube.com/watch?v=zltvWcctE6g

Despite finding the drama difficult to film, Elba clearly has a lot of affection for John Luther, saying he’s like Batman – “but without the mask and the funny ears”.

“London becomes Gotham city, the bad guys become the Joker," he said. "And here is this crusader character who rolls in in his Volvo. It's not a Batmobile but it has those characteristics, so when I put the coat on I feel like I'm playing a superhero to some degree.”

Luther series five will air on BBC1 at 9pm on New Year's Day