Police said on Monday they were investigating allegations by three transvestites that Brazilian football star and AC Milan forward Ronaldo [Images] threatened to harm them after he took them to a Rio de Janeiro motel.

Police told a news conference they were also looking into an accusation by the 31-year-old player that one of the three men tried to extort 50,000 reais (14,900 pounds) in return for not telling the media about the incident.

Ronaldo, who is back in his hometown recovering from an injury, left a nightclub in the posh Barra da Tijuca neighbourhood early on Monday with three call girls, only to find out at the motel they were men, according to authorities.

He then offered each of them 1,000 reais to wrap up the matter, but only two of them accepted his offer, police said.

"I have to check both sides of the story, the transvestites' version and Ronaldo's," Carlos Augusto Nogueira, chief of the police precinct investigating the incident, told a news conference.

"Ronaldo said he is not good in the head and that he is going through psychological problems because of his recent surgery," he said.

In a statement, Ronaldo said he was a victim of extortion and would take all possible steps to clear his name, according to the Web site of the Globo television network.

Representatives for Ronaldo were not immediately available for comment.

The three-time World Player of the Year suffered a career-threatening knee injury in February in a match against Livorno. Ronaldo suffered a similar injury in his right knee when playing for Inter Milan in 2000.

(Reporting by Rodrigo Viga Gaier; Writing by Elzio Barreto; Editing by Eric Walsh)

Image: Brazilian newspapers showing pictures of Ronaldo and transvestite Andre Luis Ribeiro Albertino, also known as Andreia Albertine in Rio de Janeiro on Tuesday. Photograph: Vanderlei Almeida/AFP/Getty Images