A FILM is to be made about the Wearside Jack hoax that derailed the hunt for the Yorkshire Ripper and allowed Peter Sutcliffe to continue killing.

The movie will tell the story of John Humble, who taunted detectives hunting the serial killer in 1979 and shifted their attention from Yorkshire to the North-East.

It will be based on Mark Blacklock’s recent novel ‘I’m Jack’ and star Welsh actor Celyn Jones, who is co-writing the screenplay with the author.

Film rights have been bought by movie company Mad as Birds and producers are set to visit Wearside as they research the film with Mr Blacklock.

VIDEO: Assistant Chief Constable George Oldfield listens to the Wearside Jack tape during the hunt for the Yorkshire Ripper

He said: “I have used a lot of documentation, some of which I have written myself, some of which I have borrowed, to create different levels of evidence.

“It is a slippery book, Humble is an unreliable narrator – but how could he be anything else?”

While police were hunting for the brutal killer who began murdering women in 1975, Humble, an alcoholic from the Ford Estate in Sunderland, infamously posted a cassette to Assistant Chief Constable George Oldfield, of West Yorkshire Police.

He said in the two-minute recording: “I’m Jack... I have the greatest respect for you George, but Lord! You are no nearer catching me now than four years ago when I started.”

Officers subsequently interviewed 40,000 men in the search for the man with the Sunderland labourer’s Wearside accent.

Mr Blacklock, an English Literature lecturer, said: “My dad was interviewed by the police, along with everyone else, but I didn’t know that until I spoke to him about my interest in the case much more recently.

“The voice really stuck with me when I heard it. It was a voice that I’d grown up hearing but it was all wrong, excessively intimate and corrupted and in black humour.”

Sutcliffe, of Bradford, was quizzed about the murders but eliminated due to his accent and killed three more people while investigations continued in the North-East.

He was caught by chance in 1981 and found guilty of murdering 13 women as well as attempting to murder seven others and remains behind bars.

Humble, 59, was unmasked as the hoaxer in 2005 because a cold case team matched DNA he gave when he was arrested in 1991 for being drunk and disorderly with an item sent by Wearside Jack.

He was jailed for perverting the course of justice, serving half of his eight-year term.

Celyn Jones, who starred as Dylan Thomas in the York-based firm’s 2014 biopic Set Fire to the Stars, tweeted: “It's a brilliant and unique novel by @DrBlacklock , we're confident the film will be that too.”