"I've done something really stupid in my personal life," the AC Milan player said in an interview with Globo television on Sunday.

"We are all subject to making mistakes and I made a mistake in looking for this. I did not at any moment know they were tranvestites," the 31-year-old added in his first public appearance since the incident last Monday. "I cried a lot afterwards. I was incredibly ashamed."

The police have said they are considering charging one of the transvestites with extortion and stealing Ronaldo's driving licence.

Ronaldo admitted the incident had done irreparable damage to his reputation.

"This was the worst decision of my personal life," he said. "It took on a very big dimension and had worldwide repercussion. It will stain my personal life forever.

He said the fateful evening had began after he had a ‘silly’ fight with his girlfriend. "I did not know they were transvestites, I'm completely heterosexual," he said. "When we got to the place, I concluded that they were transvestites.

"I tried to stop there and go home -- it was here that the extortion started. I wanted to finish by paying what we had agreed. Two accepted but the third didn't want to accept and asked an absurd quantity for it not to come out in the media."

Ronaldo added: "I preferred to face the situation head on rather than be extorted."  He said his girlfriend had reacted furiously, though she later supported him. "When I told her the story she swore at me. Afterwards she gave me support.”