BBC Worldwide is understood to be taking legal advice over a national ad campaign in the newspaper Metro featuring a character with a resemblance to Top Gear's Stig promoting an motoring event.

Metro, which is owned by Daily Mail & General Trust, ran a wraparound cover on Thursday featuring a full-page promotion for its low-carbon motor festival, ecovelocity, in London.

The ad features a Stig-like figure in a white racing suit –- adorned with coloured flowers to indicate the London event's "green" credentials – and helmet. The character is described as an eccentric and mysterious driver – "some say he once rode to Norway on a seal" – known only as "Clive".

"We were surprised to see the creative that Metro have chosen to promote this event and would like to make it clear that it is not associated with either Top Gear or the Stig character in any way," said a spokesman for BBC Worldwide. "We are currently assessing our options regards next steps."

The identity of Top Gear's Stig has been a closely guarded secret – only a few BBC executives including producer Andy Wilman and presenters Jeremy Clarkson, Richard Hammond and James May are said to know his name – and the "tame racing driver" is known for equally eccentric habits such as learning German while at the wheel.

Last year the BBC unsuccessfully took legal action to attempt to stop the publication of an autobiography by Formula Three driver Ben Collins talking of his time as the Stig. In a blogpost last year Wilman referred to the distinctive character as "ours" and that the corporation would look to protect the intellectual rights of the eight-year old character from "chancers".

The large-scale Metro promotion – the newspaper has a 1.4m daily national circulation with around 800,000 of that the London edition – comes at a sensitive time for BBC Worldwide, which is gearing up to promote its own Top Gear live event which is also held in London.

Top Gear is one of BBC Worldwide's top brands and was its biggest-selling TV show in the year to 31 March 2010.

Top Gear – coupled with Doctor Who and the BBC's natural history programmes – helped rake in £147.3m in revenue for BBC Worldwide in the year to 31 March 2010. This represented a 15% year-on-year increase in revenues, while profits from these brands rose 33.8m year on year to £51.5m.

Metro declined to comment.

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