Ruby Wax says OJ Simpson’s agent told her he “knew the truth” about his alleged double-murder.

The comic, 70, famously interviewed Simpson – who died on April 10 aged 76 from prostate cancer – for her BBC ‘Ruby Wax Meets…’ documentary series, and claims the former NFL running back’s agent Mike Gilbert dropped a massive hint his client killed his ex-wife in 1994, when she was found dead alongside her 25-year-old waiter friend Ron Goldman.

She said in an article she wrote for The Sunday Times about her time filming with Simpson in 1998 – four years after he was cleared in a criminal court of the knife murders of his former partner Nicole Brown Simpson, 35, and her 25-year-old pal Ron Goldman: “Gilbert told me that he ‘knew the truth’. He later released a book claiming that Simpson had confessed to killing his ex-wife.”

Ruby also opened about the now-infamous scene in her documentary in which Simpson pretended to stab her in the style of Alfred Hitchcock’s 1960 horror film ‘Psycho’.

It was shown in the conclusion of the show, after Ruby tells viewers: “After we finished filming, Simpson said to me that he has a surprise for me – and I genuinely was surprised.

“I think it was his idea of a joke.”

The show then cuts to Simpson knocking Ruby’s hotel door – which she opens to find him wielding a banana like a knife above his head and bringing it down in a stabbing motion while making screeching noises to imitate the strings that soundtracked the shower stabbing scene in ‘Psycho’.

The show ends with a close-up of Simpson looking wide-eyed and crazed.

Ruby said in her piece for the Times: “After I'd returned to my room at the Hyatt, following an odd day's filming during which he asked our driver to take us around his old Brentwood neighbourhood in a Ford Bronco, remarkably similar to the vehicle watched by 95 million viewers during his televised police car chase, he said he had a surprise for me.

There was a knock at the door. It was Simpson, making stabbing motions with a banana held above his head while screeching, in the vein of the famous shower scene in Alfred Hitchcock’s ‘Psycho’.

I wasn't scared; I just thought he was insane. I also immediately thought that this was very good television.

Our producer, who was outside my room with him, said Simpson was originally looking for a knife because that would have been a funnier joke, but he had to settle for a banana instead. I could have been the first person to be killed by fruit.

Afterwards, I spoke to his agent, Mike Gilbert, who had accompanied us during filming. Both he and Simpson were masters of doublespeak. They would try to confuse me by talking in riddles.

After the stabbing incident, Gilbert told me that ‘OJ is a real kidder’ and he often liked to imitate films. I said: ‘Oh, like ‘Psycho?’ He tried to tell me he was re-enacting a scene from ‘Cats’. There wasn’t even a ‘Cats’ movie out at the time! So both of them were kind of loony.”