THEY are the ultimate showbiz outsiders:

two Scottish pranksters who fooled the music industry into believing they were a Californian hip-hop duo before dropping from sight. Now set for legitimate fame thanks to a movie about their antics, the pair are preparing for a comeback and plan to retake the world of rap - this time with no fibs.

Documentary The Great Hip Hop Hoax, which tells the true story of Gavin Bain and Billy Boyd, has just opened in cinemas across the country.

Unhappy that they were not accepted by the music business because they delivered provocative rhymes in their native Scottish accents, they decided to pass themselves off as Americans, called themselves Silibil N' Brains and concocted a fictitious music career history. It was a latter day Great Rock and Roll Swindle.

They started acting loudly and aggressively - as they thought American hip-hop artists would - and got away with it, even capturing £75,000 advances from Sony UK in 2004 to pursue "the dream".

For two years they adopted fake Californian accents and lived out a carefully crafted lie to try to get one over on the record industry.

They embarked on a remarkable journey that saw them rap alongside Eminem, party back stage with Madonna and be tipped as among the next generation of rising stars.

By 2005 they claimed to have recorded enough material for three albums but they released nothing. Until now.

Silibil N' Brains were never rumbled. It was because of the fear of exposure that they broke up without releasing a single track. Others say they were actually quietly dropped by the record company.

Boyd fled to Arbroath to marry his girlfriend. Bain was left almost penniless, before eventually writing a highly fictionalised "tell-all" account of their adventures called California Schemin'.

Now they are back together, without the Californian drawl, for the film. They have made an album, Dirty Rotten Scoundrels, due out next month, and are playing live.

Boyd now juggles work on North Sea oil rigs with his music and lives in Arbroath with his wife, Mary, and two children.

On Friday, they were in Dundee for a live Silibil N' Brains performance but Boyd says: "I have a great balance of family, work and creative time."

Bain has no such balancing act to perform as he remains a full-time musician.

He said: " I'm having a laugh doing exactly what I want. I wake up, roll out of bed into my studio, make a beat, write songs for myself or others, sell beats, market my record and help fans and other musicians.

"Then I skate, freestyle, battle rap, train and have a laugh - it isn't any big deal to take a few minutes out to answer some questions about the past and future, or turn up to a screening and blow minds with killer rhymes."

He believes too many musicians care more about the fame and money than their musical output.

"The hope lies in those artists who don't wait around to be saved, but get up and get out there. Silibil N' Brains prove that if you are truly talented and believe in yourself that nothing will get in your way," said Bain.

Of the resurrected Silibil N' Brains and the new album, Bain says: "It felt like pure fire. The film had inspired us to prove to people that there was no hoax when it comes to the skills."

Boyd and Bain started out as wannabe rappers at art school in Dundee in 1999.

Their intricate plan to pose as bogus American rappers was hatched after an audition in London. It is claimed they were laughed at and described as the "Rapping Proclaimers".

Documentary film-maker Jeanie Finlay, whose father is Scottish, decided to make the movie about them after reading a newspaper article about their exploits.