Vanessa Feltz has told a Sunday newspaper how sex attacker Rolf Harris assaulted her live on TV.

Vanessa, 52, who now has her own BBC Radio 2 programme, said: “I have kept quiet for 18 years but I have decided to waive my anonymity because I hope it will encourage ­others to come forward to speak about Rolf Harris or others.”

Harris was jailed last week on 12 counts of sexual assault against four women but victims argue his sentence of five years and nine months was too short.

Vanessa spoke to Scotland Yard after hearing of the dreadful ordeal suffered by those the millionaire entertainer abused and has given police a full statement. She says she would be prepared to appear in court in any future proceedings against him to tell her story about his abuse.

The Yard has examined tape of her TV ordeal and has confirmed her story.

Vanessa has told the Sunday Express that she was assaulted by Harris when she was filming an “On The Bed” interview sequence on Channel 4’s The Big Breakfast 18 years ago, in May 1996, when she was a happily married ­rising star.

Harris, 32 years her senior and now 84, had come to the ­studio with his wife Alwen. Speaking from a hotel in Istanbul, where she is on holiday with her fiancé, singer Ben Ofoedu, 42, Vanessa explained: “It was a very relaxed show shot in a lock keeper’s cottage in east London and the bedroom was real.

“I clearly remember being excited about interviewing Rolf Harris because like millions of others I had grown up with him.

“I used to sing his famous Two ­Little Boys song with my sister and I was a great fan.

“When I was in make-up some of the girls said I should watch out because it was known in the business he had wandering hands. I said: ‘Rolf Harris? You have to be joking’.

“It all started very well. He was affable, genial, responding well to my questions.

“I was lying on cushions on the bed in a long, flowing, floor-length, heavily beaded evening dress. He was sitting very close. As the interview continued, with his wife watching and with the crew all in the room, I suddenly felt a rustling at the hem of my dress.

“I was on live television so I could not look down but I sensed that his hand was at the bottom of my dress and he was slowly gathering the ­fabric up and moving his hand higher and higher up my leg.

“He was carrying on talking as though nothing was going on, smiling and joking, as he moved his hand ­further up.

“Suddenly his hand had reached my knee and he was still going up and travelling at speed. I was so shocked. This was Rolf Harris. I could clearly see his wife. How could this possibly be happening? But, of course, as he knew perfectly well, I could not say anything.”

Her natural instinct was to put her hand out to stop him but that would have alerted viewers to what was going on. She was also extremely worried about upsetting his wife.

Speaking slowly, and clearly stressed at recalling the episode, Vanessa continued: “Then I felt his hand on my thigh. He was inching higher. I was not wearing tights or stockings and I sensed nothing was going to stop him.

“After a few seconds he had managed to get his hand inside the elastic of my knickers and I was absolutely staggered.

“Somehow I knew I had to do something but I was in the middle of an interview on live television with one of the most famous men in the country.

“What do you do? Stop and tell the viewers: ‘Rolf Harris is assaulting me’. I could not do that.

“I was also conscious that we had a lot of children watching and I could not say anything which would upset them.

“I have not a shadow of a doubt that he knew exactly what he was doing and he was getting excited about it, doing what he was doing while he was on live television.

“I realised that if I did not do something dramatic I would be literally a sitting target and his hand would have gained access to the most ­intimate part of my body.

“I was determined that was not going to happen, so before he could actually assault me intimately I had no alternative but to cut to an advert break.

“The second we went to the break I jumped away from him and got his hand out from under my dress. He didn’t react in any way at all.

“When we came back to the live interview, he carried on as if nothing had happened. He was smiling and joking. Inside, I could not wait for the interview to end. I was both disgusted and furious with him.

“I was powerless to protect myself and he knew and he was getting a thrill from it.

“What I really wanted to do was tell him ‘**** off’ and let him have a piece of my mind but he knew I could not say a single word on air.

“I had extricated myself from a serious sexual assault but he was still trying to be in control. After the interview I rushed off to the dressing room without speaking to him.

“I felt a mixture of anger and confusion. At the time I did not even ­consider going to the police. I did not think anyone would believe me against the great Rolf Harris.

“When I read the accounts from his other victims who spoke about how he assaulted them in view of others, I knew they were telling the truth because their stories were so similar to what had happened to me. I realised that he was prepared to take enormous risks to assault his victims. In fact, that was part of the thrill of it. That is part of who he is.”

Although the format of the show involved an interview on a bed, Vanessa preferred straight-talking questions to flirting with guests. She never sought Harris’s advances.

Afterwards she told her then husband, Michael Kurer, an orthopaedic surgeon.

She said: “He was ­supportive but, like everyone else, he was astounded. Rolf Harris? National treasures do not behave like that.”

After Harris’s arrest in 2012, Vanessa spoke to Scotland Yard and detectives obtained footage from The Big Breakfast.

They had hoped to introduce it as evidence in Harris’s trial at Southwark Crown Court but there was not enough time to give adequate notice to defence lawyers.

It was said in court that Harris had not offended for 20 years but the incident involving her happened 18 years ago.

Vanessa wonders if she should have taken action earlier and has said that if needed she was prepared to give evidence in future proceedings.

She added: “My only reason for speaking now is to encourage other women who have been the victims of assaults to come forward.

“Sexual predators are opportunistic. If it happens to you it has very probably happened to a host of other women and girls. Someone like Rolf will carry on unless they are shamed and stopped.”

Ben, Vanessa’s partner of eight years, said: “I am proud of the fact that Vanessa came forward. Hopefully, by speaking out this will encourage more women to think their stories will be believed.”