The Standard, owned by Associated Newspapers, published the presenter's name in its Late Prices Extra edition this afternoon.
It was repeating what chat show host Matthew Wright accidentally revealed in his show 'The Wright Stuff', on Channel 5 this morning.
Although the Evening Standard is not the first to name Jonsson's attacker, as his identity was revealed by Wright, the paper could still be prosecuted for repeating the libel if the claims are proved to be untrue
The UK tabloids have published several stories about the claim, but all have so far protected the identity of the man despite it being widely known who he is.
Jonsson made the rape claims in her autobiography 'Honest'. She decided not to name him at the last minute under legal advice.
The case has recently taken a twist, after two more women have claimed that they too have been sexually assaulted by the same man.
Details of the women's claims were published by the Daily Mail -- the Evening Standard's sister paper -- in a two-page article today.
However, instead of going to the police with the news, they went straight to publicist Max Clifford.
Clifford is understood to have told the mystery presenter to deny the allegations, after he was approached for advice following the publication of the book. The man took the advice and published a denial, without revealing his identity.
Police have since confirmed that a woman has made a formal allegation. She has said she was attacked by the same TV presenter at the centre of the Ulrika Jonsson date rape mystery. The alleged victim walked into a police station to make the complaint, according to reports.
The 30-year-old woman was spoken to by detectives for several hours. She is understood to have come forward after seeing Jonsson talk about the allegation on television. She says the alleged attack took place several years ago.
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This article was first published on brandrepublic.com