Simon Pegg is to star in a new film based on the real-life story of a psychoanalyst investigating claims of a talking mongoose.

He plays Nandor Fodor, a Hungarian-American investigator of paranormal phenomena who, in 1935, was called to the Isle of Man to investigate claims by the Irving family that they had found a talking mongoose named Gef on their farm.

Minnie Driver will play Anne, his assistant, in a cast that also includes Tim Downie, Paul Kaye, Ruth Connell, Gary Beadle and Drew Moerlin.

Nandor Fodor And The Talking Mongoose, which is now in production in Leeds, has been written and is directed by Adam Sigal.  He told Deadline: ‘Nandor Fodor And The Talking Mongoose is such a unique story that I couldn't believe it was true. There's nobody else other than Simon who could embody this character and take us on this insane journey and I can't wait to get started.’

 According to the Irvings, they found Gef – pronounced ‘Jeff’ – after investigating noises coming from behind their farmhouse's wooden wall panels. The creature  introduced itself and told them it was a mongoose born in New Delhi, India, in 1852.

The family claimed he said: ‘I am a freak. I have hands and I have feet, and if you saw me you'd faint, you'd be petrified, mummified, turned into stone or a pillar of salt.’

At one point he described himself as’an extra, extra clever mongoose’ – and at another time added: ‘I’ll split the atom! I am the fifth dimension! I am the eighth wonder of the world!’

The Irvings told stories of Gef  eating bacon and sausages, turning off the stove at night, and even riding the bus and bringing back gossip about the neighbours. 

The case drew much tabloid attention at the time, although it was widely suspected that the family’s 13-year-old daughter,  Voirrey, had used ventriloquism tricks to affect the hoax.

Among those who covered the story was Richard Lambert, editor of The Listener.

When Sir Cecil Levita, a former chairman of the London County Council, suggested Lambert’s interest in the case meant he was  ‘off his head’ and  unfit to be on the board of the British Film Institute, the journalist sued for slander, receiving £7,600 in damages, more than £500,000 in today’s money.