Rolf Harris allegedly asked a young girl "Do you often get molested on a Saturday morning?" after sliding his hand under her breast, a court has heard.

The 86-year-old entertainer is alleged to have placed his hand under the clothed breast of the teenager after she attended a broadcast of children's television show Saturday Superstore at BBC Television Centre in White City, west London, in 1983.

Giving evidence at Southwark Crown Court, the complainant recalled getting herself a drink in a room where there were others "milling about".

She told the court: "Rolf Harris came and stood next to me. He was on my right.

"He slid his hand under my breast and then said to me 'Do you often get molested on a Saturday morning?'."

"It was like a kind of cupping motion," she added.

Asked how she reacted, she said: "I was in shock. It was the last thing I had expected to happen and I did not know really what to do.

"I was a bit in shock and couldn't move and he left quite quickly afterwards."

Speaking via video-link, the complainant told the court that directly after the alleged incident she told another girl, who was "dismissive" of her claim.

She said she had also told others throughout her life but "the reaction I got from people was sheer disbelief, so I thought 'If my friends don't believe me then the police won't believe me'.".

Harris's first trial prompted her to go to the police, she said.

The jury was shown a photo of an autograph she received from Harris "with love", which she then stuck into her autograph book.

She also collected other autographs, including one from late pop star George Michael.

Stephen Vullo, defending, asked her: "If what he had done to you had shocked and traumatised you, why did you want to keep a memory and memento stuck into an autograph book of the day you met Mr Harris, your attacker?"

She replied: "I was quite shocked after the incident so again, even though it shocked me, the reaction I got from other people confused me into thinking that it maybe wasn't as bad as it was.

"But I knew myself that it was."

Harris has "no memory of this event at all", Mr Vullo added.

The alleged victim recalled that she had been "quite excited" to meet the entertainer.

She said: "I remember being quite excited that he was going to be (there), I was quite a big fan ... and I had grown up with him on the telly, so I was quite excited to meet him."

The show included a range of news items and cartoons and there were several times when celebrities "would talk with us and mingle with us", she added.