Cheeky playwright Brian Behan is to bare his bottom on national television.

His rear stars in an advert which shows him running naked into the sea off Brighton beach for his daily skinny dip.

The four-second film clip will be screened before and after episodes of Channel 4 quiz show Countdown for a year.

Mr Behan, 74, of Newark Place, Brighton, said: "I sold my bum for £1,500.

"It will drive the women mad but it was a bit chilly during filming."

Mr Behan - brother of the late Irish writer Brendan Behan - stars in one of nine clips.

They show ordinary older people doing extraordinary things to advertise Countdown's sponsors, margarine maker Flora.

Mr Behan was filmed on the beach opposite the Metropole Hotel last week.

The clip will be aired on a rota with others, including an elderly body builder and a married couple in their 60s who have black belts in karate.

Roger Troup, of London-based production agency Brewers, who filmed the clips, does not yet know when the clips will be shown.

He said: "It was fantastic working with Brian because he is such a character."

It is not the first time Mr Behan's daily skinny dip into the sea has hit the headlines.

In December he sparked an air sea rescue after a passer-by thought he was committing suicide and called 999.

But he insists his daily swim in the icy waters kick-starts his day and keeps him fit.

He is no stranger to the small screen, either. He appeared in the Firestarter video for pop group The Prodigy in 1998.

Mr Behan said: "I dyed my hair green, wore a bolt through my lip, big boots, lots of medallions and shorts.

"I then had to jump about shouting. It was great fun."