Amy (not her real name) was 17 and working in a hotel when the veteran broadcaster assaulted her during a break in the filming of an edition of It's A Knockout.
"I went along to the auditions to see if I could take part in it, and I was chosen to be a cheerleader,"
she told ITV News.
"We had afternoon tea in the town and about early evening, because I worked in a hotel, I had a staff room and I met him in the hotel where I worked."
The teenager had walked through the hotel lobby and got to the top of the stairs leading to the staff rooms when she heard "this voice behind me".
"It was him, and he started talking to me. Obviously if you work in a hotel you talk to the residents.
"Then, as I went to go through to touch the door-handle, he pushed me up against the wall and he tried to force himself on to me. He grabbed hold of me and he started kissing me and then he tried to force himself on me.
"I struggled, I tried to push him away, and it was only the fact that there was someone walking along the corridor and the floors creaked that he stopped and I managed to get away.
"That was 40 years ago and I never told anyone."
She added: "I will never, ever forget that voice and that's the part … over the years every time I've heard his voice on the television, on the radio, I just think: 'How can you do it, how can you be like that in full view of everyone after everything you've done?'"