The 33-year-old thespian, who shot to fame as romantic hero Will Ladislaw in Middlemarch, plays the bumbling Ali Baba in a lavish adaptation of Arabian Nights on BBC One.

And despite his unglamorous character, Sewell says he loved every minute of the show.

"It was fantastic," he says. "It was a bit like doing panto because we were all allowed to dress up and wear silly beards."

Uncomplicated character

As the good-hearted Ali Baba, Sewell discovers a hidden cave filled with treasures and outwits the villain of the piece, Black Coda and his murderous gang of 40 thieves.

The film was shot amid the rugged terrain of the Cappadocia region of Turkey - a location also used for the Star Wars movies.

Much of time, Sewell had only a bad-breathed camel to share his scenes with. But, he says, he relished the opportunity to play such an uncomplicated character.

"Ali Baba is just good-hearted and straightforward and, as it turned out, not really that easy to play. He's just a nice guy - not the sharpest note in the symphony."

The tale of Ali Baba and the 40 Thieves is a tale within a tale - just one of the magical stories narrated by Sheherazade, the Sultan's wife, to save herself from execution.

Among the other tales Sheherazade tells are The Three Brothers, about jealous siblings who learn the strength of unity; a comedy about a hunchback called Bac Pac; and the story of Aladdin.

Sewell - who won an Olivier award for the part of Septimus Hodge in Tom Stoppard's West End production of Arcadia - says the humourous side of Arabian Nights came as a breath of fresh air.

"What I love about this production is that the tone is very light. The subject matter is sometimes dark but the tone remains light.

"There's a kind of tongue-in-cheek aspect to it. So you play it straight as you can but it's still quite funny."

Down-to-earth

Sewell has also starred alongside Kiefer Sutherland and William Hurt in the sci-fi thriller Dark City and with Joseph Fiennes in Martha - Meet Frank, Daniel and Laurence.

Most recently, he has been in the US filming Bless This Child with Kim Basinger and Christina Ricci, in which he plays the leader of a satanic cult.

But despite his Hollywood success, Sewell says he tries to keep his feet on the ground - and in London.

"As long as you never get to expect any kind of treatment, then your ego can survive quite happily without getting too bloated," he says.

"I've worked all over the world in the past few years but London is where I love. If you live in a place that's completely dominated by the film industry then it's bound to affect you.

"I've seen people turn into jerks and I think it's more important than aything else that I remain the kind of person I like."

Arabian Nights can be seen on BBC One on 30 April at 18.30 BST and 1 May at 18.20 BST.