Terrified Des viewers ‘scared to sleep’ after watching David Tennant as serial killer Dennis Nilsen

DES fans have been left ‘scared to sleep’ after watching David Tennant as killer Dennis Nilsen.

The ITV drama focuses on the notorious serial killer, who murdered more than a dozen men at his London home from 1978 until 1983.

David, 49, gives a chilling performance as Dennis, so much so, some have been left unable to sleep.

Taking to Twitter, one wrote: "Oh it’s time to scare myself silly again Face screaming in fearwatching @itv #Des I’m hoping @TwiningsUK Sleeping symbol is going to help this evening #scared #itv #itvdes #tea #twinings #sleep."

Another tweeted David's co-star Daniel Mays, who plays the detective in charge of the case, DCI Jay: "@DanielMays9 Just watched Des, scared to go to sleep now!"

A third added: "I can attest that reading Dennis Nilsen’s Wikipedia page before turning in doesn’t make for a great night’s sleep. #Des."

It's no surprise that viewers couldn't sleep, after chilling scenes saw Dennis defend necrophilia after carrying out despicable acts with the corpses.

Brian Masters - Dennis' biographer - asks the killer about having sex with the bodies of his victims.

Dennis insisted it "wasn't about sex" and accused Brian of trying to find "simple answers".

But Brian - played by Jason Watkins - replied: "I'm not trying to simplify anything but you did have sex with these young men after they died."

Dennis then chillingly replied: "No, I did not. Did I enjoy them? Yes.

"Did I gain some sort of satisfaction from looking at their naked bodies next to mine in the mirror? I didn't penetrate them.

"The only thing I did was squeeze the life out of a human being, that was wrong, that was unforgivable. I'll be properly punished for it."

He continued: "What I did with a corpse was neither here nor there. If you're more disgusted by what I did to a corpse than what I did to a living man, then your moral system is upside down."