The woman, who is now 63, told Preston Crown Court she visited the television complex in 1965 to take part in a talent show when the alleged attack happened.

"We were excited to be in company of famous people. Two excited young teenagers who had just failed an audition," she told the court.

The witness said the atmosphere was "quite chatty, full of our recent experiences". She said she was "excited to be in the company of a famous actor."

Describing what happened, she said: "He (Roache) grabbed my arm roughly. He opened another door and that happened to be a men's toilet. I was worried."

She said, after pulling her inside the toilet, Roache assaulted her. "I was a little bit in shock. I didn't really understand.

"My paramount feeling was to get out of there. I should not be there. I remember hurriedly leaving the room."

She said that afterwards, she did not tell her friend what had happened because she felt ashamed and afterwards, because she was "naive" believed at the time they were having some sort of relationship.

She says she went to the police much later when she heard that someone else had reported that Roache had raped her.

Roache,  81, from Wilmslow, Cheshire, is on trial accused of raping one girl and indecently assaulting four others. He denies all of the charges.

Helen Pidd is the Guardian’s Northern Editor and was at Preston Crown Court, she says at least some of his colleagues are expected to voice their support: