The Museum of London is displaying a coin found by the River Thames that could have been used as a “brothel token” in Roman London 2,000 years ago.

The token shows a man and a woman having sex on one face and the other face has the Roman numerals XIIII. The woman seems to be lying on the couch and a man is positioned behind her.

The museum said that the coin was approximately the size of a UK 10 pence piece, or the size of a U.S. dime, and was probably the only token of its type to be found in Britain.

Senior curator Caroline Mcdonald said Thursday that it is impossible to precisely determine what the coin was used for, according to AP, and she said that it was possible that brothels existed in London when the coin was in circulation after the Roman invasion of Britain in the 1st Century A.D.

However there is still debate among experts of the precise use of the Roman spintria, although they are normally regarded as brothel tokens which were exchanged for sex. Experts have suggested that the coins could have been used as gaming tokens.

“If this item is indeed a brothel token, the reverse numeral may indicate the price of the service shown on the front of the token,” the museum said in a statement released Jan.5.

“This is the perfect archaeological object. It’s sexy and provocative in the best sense of the word. The lot of a Roman sex slave was not a happy one and objects like this can help the Museum of London provoke debates about issues that are relevant to the modern city and its visitors. Museums should engage with these more grown-up and sometimes less comfortable topics,” Mcdonald said in a statement.

The coin was discovered recently by a man with a metal detector looking for objects near Putney Bridge, and will be on display at the museum until April 2012.