Harry Potter star Robbie Coltrane transforms into Orson Welles

He played the giant Hagrid in the Harry Potter movies. Now Robbie Coltrane has been transformed into another cinematic giant – Orson Welles.

Images show the 70-year-old Scottish star in false beard and flamboyant clothing as the celebrated American actor and director.

A one-off film for Sky Arts tells the unlikely story of how Welles, considered one of the greatest filmmakers of all time for works including Citizen Kane, briefly went missing in Norwich in 1972.

Welles came to Britain in 1972 to make a series of mystery dramas with Anglia Television. 

It is believed he took the job because he was out of money and needed to raise funds for his 1973 documentary about forgery, F For Fake.

But while he was there he apparently went missing. The urban myth is that he was abducted. 

Robbie told Radio Times: ‘The story goes that he was kidnapped by a German terrorist organisation, something like Baader-Meinhof.

‘The wonderful thing about it is that nobody knows if it’s actually true. Even people who were at Anglia in those days are very vague about it. They say, “I wasn’t there that day”.’

The drama is the fourth episode of the new series of Urban Myths, which dramatises some of the strangest stories from the entertainment and arts worlds. 

One image shows Robbie as Welles on set and pouring a drink, while another sees him on location in hat and cape and holding a cigar.

Welles died in 1985 aged 70. His other films included The Magnificent Ambersons, The Third Man and Touch of Evil.

Robbie played Hagrid in all eight Harry Potter films and is also known for his portrayal of Fitz in the ITV series Cracker.