Inquiry puts further pressure on beleaguered presenter after he receives a final warning from the BBC over N-word row

Jeremy Clarkson's controversial "slope" reference in an episode of BBC2's Top Gear is to be investigated by the media regulator in a move that is likely to heap further pressure on the beleaguered presenter.

Top Gear producer Andy Wilman has already expressed regret for any offence caused by the remark, made after Clarkson and co-hosts Richard Hammond and James May built a bridge over the River Kwai in the motoring show's Burma special broadcast in March.

As an Asian man was seen walking along the bridge, Clarkson said: "That is a proud moment, but there's a slope on it." Hammond replied: "You're right, it's definitely higher on that side."

Media regulator Ofcom has launched a formal inquiry after it received two complaints about the broadcast on 16 March this year.

Clarkson said he has been given a final warning by the BBC following the most recent controversy to surround the show after he used the N-word in an outtake.

The BBC faced further calls on Tuesday for Clarkson to be sacked, with profits from the show to be given to an anti-racism charity.

The presenter was forced to apologise last week, issuing a video "begging for forgiveness", following claims that he had used the word while he recited the nursery rhyme, Eeny, Meeny, Miny, Moe in a clip that was not used on the show.

Clarkson said in his Sun column on Saturday: "I've been told by the BBC that if I make one more offensive remark, anywhere, at any time, I will be sacked.

"And even the angel Gabriel would struggle to survive with that hanging over his head. It's inevitable that one day, someone, somewhere will say that I've offended them, and that will be that."

Clarkson was reprimanded by BBC bosses after being summoned to a meeting with the director general, Tony Hall, and the BBC's director of television Danny Cohen.

It was the latest in a long line of controversies surrounding the show and its best-known presenter.

The "slope" remark was initially picked up by actor Somi Guha, who instructed lawyers to make a formal complaint.

Lawrence Davies, director of the law firm Equal Justice, which made the complaint, sent a further letter to the BBC on Tuesday calling for Clarkson and several of his BBC colleagues to be sacked for "gross misconduct" and called for profits from the show to be given to an anti-racist charity.

Davies claimed there had been "repeated" incidents of racism on the BBC2 show at the expense of Germans, Mexicans and Asians, among others.

The letter, on behalf of Guha and three others – Anthony Robinson, a former director of the Equality and Human Rights Commission and US entrepreneurs Fred Jacobs and Richard Rogers – said Top Gear "specialises in making a profit from deliberate but deniable racism".

It described the latest incident, Clarkson's mumbled use of the N-word, as a "national disgrace" and said the programme "encourages and legitimises raciest stereotypes and attitudes".

It added: "Our clients ask the BBC to investigate the deliberate use of racism on the show and if this is proven to dismiss those [responsible] and to return the profits from those particular shows and to donate them to an anti-racist charity."

In his apology, Clarkson said he did "everything in my power not to use that word … obviously my efforts weren't quite good enough".

Davies said: "There isn't another mainstream programme on British television where you would even contemplate using the N-word. If it's not creating racism within our society, it's encouraging it. Children watch this show – what values are they picking up?"

In a statement, Wilman responded: "When we used the word "slope" in the recent Top Gear Burma special it was a light-hearted wordplay joke referencing both the build quality of the bridge and the local Asian man who was crossing it.

"We were not aware at the time, and it has subsequently been brought to our attention, that the word 'slope' is considered by some to be offensive and although it might not be widely recognised in the UK, we appreciate that it can be considered offensive to some here and overseas, for example in Australia and the USA.

"If we had known that at the time we would not have broadcast the word in this context and regret any offence caused."

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