Radio 1 DJ Scott Mills’ show is being investigated by the broadcasting watchdog over jokes about Essex girls.
The BBC programme has sparked complaints that the quips, aired last month, were sexist and derogatory.
Jokes included “What’s the first thing an Essex girl does in the morning? Goes home”, “Why does an Essex girl wear knickers? To keep her ankles warm”, and “What does an Essex girl say after her doctor tells her she is pregnant? Is it mine?”
The jokes were broadcast as Scott and fellow presenter Chris Stark stayed on air for 24 hours in a marathon show to raise money for Comic Relief.
An Ofcom spokesman said: “We’re investigating whether this programme breached our rules on generally accepted standards.”
Bobby Norris, from reality TV show The Only Way Is Essex (Towie), made the quips after the hosts of the Radio 1 show told listeners he was there to say a “couple of sets of Essex girl jokes”.
Scott had told listeners: “I’d like to point out, before anyone complains, this is a person from Essex, living in Essex on a show (Towie) about Essex.”
He added: “I’m enjoying this so much.”
Other jokes, which were sent in by listeners, included: “What’s the difference between an Essex girl and an ironing board? Occasionally you have trouble getting the legs apart on an ironing board.