The BBC Secret Agent film unmasking the extremist Far-Right British National Party's violent tactics in Bradford could provide a positive platform to improve race relations, according to a leading churchman.

Dr Philip Lewis, the inter-faith advisor to the Bishop of Bradford and member of the University of Bradford's Depart-ment of Peace Studies, said "crude and violent" statements in the film had brutally exposed the BNP's failure to re-invent itself as a respectable political party.

"The programme has cleared the air but there remains a challenge," said Dr Lewis. "There are tensions and defects and we have to devise a vocabulary to talk responsibly about those defects.

"The programme could be an incentive to work harder. If we don't, real grievances can't be addressed. Extremist groups come along and exploit those grievances.

"The programme should be a goad for soul searching. A lot of people in Bradford have grievances which aren't being addressed and that's been exploited by the BNP. It raises sharp questions for us as a district."

Dr Lewis showered praise on BNP organiser Andy Sykes who despite grave misgivings had remained undercover in the party to expose its real agenda.

"He took considerable risks to enable the programme to be made," he said.

"I was very impressed by him. Here's an ordinary guy taken in by their rhetoric but who then becomes aware of their agenda and waits to expose them."

Dr Lewis said the film posed a big challenge in Bradford.

It featured a BBC reporter who spent six months undercover with the BNP.

Jason Gwynne was able to record a Bradford BNP member, Steve Barkham, confessing to taking part in a racially-motivated attack on an Asian man during the 2001 Bradford riots among other things which are being investigated by West Yorkshire Police.

Both Mr Barkham and Dave Midgley, a BNP candidate for council elections, have now been expelled by the party.

Mr Griffin continued his tirade against the Islamic faith on Thursday, branding it "a monster in our midst."

He later apologised unreservedly for some comments made during the documentary.

Dr Lewis said Mr Griffin's comments about Islam had been a "crude aricature."

"What this shows is there's a challenge for us all to develop religious literacy," he said. "What Griffin did time and time again was to confuse cultural abuse, anti-social behaviour and disaffected youth, white and Asian, in histrionic terms. It's a very dangerous game

"The challenge is to start an informed and adult understanding of religious traditions. Many of my Muslim friends will be relieved that Griffin's outrageous sentiments have been exposed."

Dr Lewis said he was confident that the Muslim community had the maturity to realise that they, too, had a responsibility to challenge Islamaphobic sentiments.