Venessa Feltz has revealed that Mohammed Al-Fayed came on unbelievably hot and heavy to her at a Bar Mitzvah in 2002 and invited her upstairs.
The former Harrods owner, who died last year, has been accused of sexually assaulting more than 20 women who worked at the department store.
Ms Feltz, 62, said on Channel 5s Jeremy Vine Show on Friday that she remembered the menacing nature of his behaviour towards her.
The broadcaster said he had made a bee line for her and described his approach as insistent, adding that it was extremely difficult to extricate myself from it.
Ms Feltz previously opened up about how Rolf Harris groped her live on air.
Vanessa Feltz (pictured) opened up about how Mohammed Al-Fayed came on unbelievably hot and heavy to her at a Bar Mitzvah in 2002 and invited her upstairs
Jeremy Vine (pictured) recalled being offered Viagra by Al-Fayed after interviewing him on Radio 2
Host Jeremy Vine, 59, recalled being offered Viagra by Al-Fayed after interviewing him on Radio 2.
He said the billionaire opened the palm of his hand and had a pill in it, saying: That, for you, is Viagra, you look like a man who needs it.
He added that the pill wasnt blue, speculating that perhaps it was a tic tac, and that it was a really weird joke.
Their comments came as they discussed a BBC investigation into the allegations against Al-Fayed, which include claims from five women that he raped them.
Vanessa Feltz said: This doesnt compare in any way, but I just remember immediately, as soon as I heard there was this documentary, that I had been invited to a Bar Mitzvah in 2002, and for some reason my partner didnt go with me, I dont know why.
And Mohammed Al-Fayed was there, and he made a beeline for me, and he came on unbelievably hot and heavy.
And I looked into this, he was 73, I was 40. I had a partner, I was not interested in him in any way whatsoever. Not at all.
And he said to me that he had an apartment upstairs, and I think I was at Claridges at the time.
And he said, come up, come up, come up, you. I want to show you the view, I want to show you the terrace, I want to show you the thing.
Vanessa Feltz (right) told her fellow panelists Carrie Grant (left) and Reem Ibrahim (centre) that she remembered how menacing and insistent the Harrods boss had been
Jeremy Vine (pictured) noted how there had been a lot of sympathy for Al-Fayed after the death of his son Dodi in a car crash with Princess Diana 1997
And we were in the middle of a Bar Mitzvah, and I said, you know, no, thank you, absolutely not, but no thank you, you know I was trying to be polite, but I just remember the kind of menacing nature of it…
She added that he was very emphatic and that she had not flirted with him.
Ms Feltz continued: I hadnt been sort of coquettish to him. I didnt fancy him. I wasnt interested in him.
I didnt want to see his apartment. I was I was at a Bar Mitzvah. You dont just leave a Bar Mitzvah to go up to look at someones apartment in the middle of a… the whole thing was just so irregular, thats why I remembered all these years later.
But what I mostly remember was the very insistent tone of it and the repetitive tone of it and the fact that I it was extremely difficult to sort of extricate myself from it.
And when I heard about this, all these women, obviously that did not happen to me at all.
But I did think, gosh, if you were in a subordinate position, you were young, you worked for him, it would be very, very difficult.
Vanessa Feltz (right) said she had tried to be polite but she was not interested in him in any way whatsoever
Mr Vine pointed out that at the time it had been just five years since Al-Fayed had lost his son Dodi Fayed in the car crash that also killed Princess Diana in Paris.
Ms Feltz explained that she had wanted to be polite towards Al-Fayed as he was an older man, and to let him down gently.
She said: As he was an older man, you didnt want to be too you know, you dont want to no, God, no, I dont want to go up anywhere near you, dont be ridiculous! You wanted to be at least polite.
He noted that there was a lot of sympathy for him and a bit of protection around him after that period.
Presenter Carrie Grant said: There was a time, in telly and in business, powerful men could kind of put you into those positions where you felt really vulnerable, and you had to have some strength to pull your way out of it.
22-year-old Reem Ibrahim added: I think its the problem is men who are in positions of power, who could hold something against you, so they can take away an opportunity, they can, or the opposite, they can actually give you an opportunity.
Those particular situations, men will often use those positions in order to try and lure young women.
Yes, it does still happen, but definitely not to the same extent, I think, that it used to.
Carrie Grant (pictured) said how there was a time when powerful men could kind of put you in those positions where you felt really vulnerable
Reem Ibrahim (pictured) said it does still happen, but definitely not to the same extent
Last year, Ms Feltz spoke out about how she was groped by Rolf Harris on live TV as his wife stood just feet away.
She described how the convicted sex attacker assaulted her during a 1996 interview on Channel 4s The Big Breakfast.
Harris, who died last year of neck cancer at the age of 93, pulled up her dress and tried to touch her knickers during a segment called On The Bed.
She told TalkTV Drivetime how Harris had been crunching her dress and pulling it further and further and further up my legs.
And you can actually see in one of the pictures me, taking a blue cushion and putting it between us to try to make some space between me and him. And he completely ignored it, she added.
The broadcaster said she could feel his hand going past my knees up to my thighs while Harriss wife was standing in the same room as them.
She said: I didnt know what to do because I knew that I couldnt say, Get your hand off my leg or What the hell do you think youre doing? or Get off me and I also couldnt jump off the bed because I was all mic-ed up and its a live program. I didnt know what to do at all.
I tried, as you can see, to put the cushion between, that was no good. I couldnt move any further away because you can see I wouldve fallen off the edge of the bed… his hand meanwhile was getting closer and closer and closer and closer and closer.
And then it got to the edge of my pants, my knickers, or whatever. My lingerie, and I knew, that if I didnt do something immediately, it was going to be a proper full-on assault.
The 61-year-old, who says she reviewed the incident when she was interviewed by police while officers were investigating Harris, said she was so concerned about what was happening that she told the crew to cut to a commercial break early.
She said: I didnt say a single word, he didnt say a single word, his wife didnt say a single word and then when we came back after I just got back on the bed and we carried on again.