BBC chiefs received complaints about Gregg Wallace’s lewd behaviour on Strictly ten years ago, but let him stay on the show.
Wallace, 60, who was paired with dancer , was accused of making sexual remarks in 2014.
He was also filmed during training boasting that he never wore underwear.
MasterChef co-host John Torode said the scandal was “upsetting”.
In the clip, Wallace says to pro partner Aliona Vilani: “I haven’t worn a pair of pants since I was about 17-years-old.”
He then gestures to his crotch, prompting a visibly uncomfortable Aliona to ask, “You for real?”
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It is understood at least one member of the hit show made the situation clear to Strictly bosses and held meetings with them over his behaviour early on during the 2014 series.
But Wallace, who last week stepped down as MasterChef co-host amid a string of sexual harassment allegations, continued competing before he was the first celeb eliminated in week two.
The Sun’s latest revelations raise fresh questions for the Beeb — both over its handling of Wallace and other abuse allegations on scandal-hit Strictly.
A show insider said yesterday: “The situation around his behaviour was made very clear to Strictly staff.
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“It included sexual comments which made people feel incredibly uncomfortable. It created a very strained atmosphere backstage.
“As I understand there were a number of meetings to discuss the issues.
“In the end, Wallace remained on the show but not for much longer, given he was eliminated so quickly.”
Our source added: “Why did Strictly bosses allow Wallace to stay on the show? That’s one of the many questions the BBC must now answer.”
When we asked the BBC about the complaints, a spokeswoman said bad behaviour “will not be tolerated”.
Wallace was partnered with Russian dancer Aliona, 40, who won the Glitterball trophy twice while a professional on the show. For one dance he performed in a chef’s outfit.
After the pair lost a dance-off she retweeted 62 messages which said she should have had a better partner.
Aliona quit after winning in 2015 with The Wanted singer Jay McGuiness.
Speaking about his experience on the show, Wallace later said: “I didn’t particularly enjoy Strictly.
“I love dancing but if I were paired with somebody who liked me, then I would have done better.”
Despite the complaints lodged with Strictly bosses, Wallace’s career at the BBC was unaffected.
But the former greengrocer, who began presenting MasterChef in 2005, stands accused of making sexual comments to staff and guests across multiple programmes over 17 years.
Gregg Wallace - MasterChef scandal in Brief
GREGG Wallace has stepped down from his MasterChef hosting role after a probe into alleged inappropriate behaviour. But what's the situation?
Regular MasterChef host Gregg Wallace is currently the subject of a probe after an investigation was launched into his alleged misconduct over a number of years.
Gregg has been accused of making sexual remarks to 13 colleagues including Beeb anchor Kirsty Wark - accusations he denies.
The 60-year-old has now stepped away from the BBC show while historical misconduct allegations against him are investigated.
Yet the former greengrocer spoke out on social media to blast the "women of a certain age" who he claimed were behind the allegations.
The cooking show’s production company, Banijay UK, has said law firm Lewis Silkin would lead the investigation into Wallace’s alleged misconduct.
He also faces a number of allegations of groping colleagues and contestants.
Wallace stepped down from his MasterChef co-hosting role after 13 women — including former Newsnight presenter Kirsty Wark — came forward and made claims against him.
Yesterday The Sun told how he allegedly thrust his groin at the face of beauty therapist Emma Phillips-Jennings, 42, when she appeared as a contestant on MasterChef in 2009.
Horrified Emma, of Herne Bay, Kent, says the scenes were edited out.
She also said Wallace made a sexual joke about meat at the same time.
Another woman has claimed that he groped her while she cooked.
And a woman called Lisa — not her real name — claims Wallace touched her inappropriately while they were on BBC show Eat Well for Less in 2015.
She told the BBC: “He brushed past me at the checkout, and touched my bum with his waist and penis and laughed and said “Oooh you liked that didn’t you’.
“It was the way he reacted. Other people would’ve said, ‘Oh, I’m sorry, can I squeeze by’ which would’ve been OK.
“But I wasn’t OK about it. When I finished the shoot, I felt it was slimy, disgusting. He just didn’t need to touch my body, it made me uncomfortable.”
Wallace has even been accused of at one point walking into the MasterChef studio completely naked with only a sock covering his privates.
Amid the mounting claims against him, at the weekend Wallace posted a message online insisting the people making them were “middle class women of a certain age”.
He later apologised for the remarks.
Sir Keir Starmer was asked about Wallace’s comments at Prime Minister’s Questions yesterday.
He said: “One of the greatest barriers women face when coming forward about sexual harassment in the workplace is having confidence they will be taken seriously.
“Everybody should be treated with dignity and respect.” Wallace denies any behaviour of a sexually harassing nature.
MasterChef producer Banijay UK is investigating the raft of allegations which have been made against the married dad of two.
A BBC spokesperson said: "In recent days there has been concerning allegations made via the media about the alleged conduct of Gregg Wallace, many of which relate to shows made for the BBC.
“These media stories are running alongside an independent investigation, which was instigated after formal complaints were made direct to the BBC and were referred to Banijay UK for further investigation.
"We would like to thank those who have had the courage to speak out.
"It can be hard to come forward, but we want to assure everyone who does that we will treat anything raised with us with the greatest possible care.
“Banijay UK launched the review because they have the direct contractual relationship with Gregg Wallace. He is not employed by the BBC.
"When issues have been raised with the BBC we have taken action, referring issues to the relevant production company and challenging his behaviour directly as has been widely reported.
“We hope Banijay UK’s independent investigation can be concluded rigorously and as swiftly as possible.
We want the review to follow due process and ensure fairness to all involved.
“We will provide whatever assistance we can to the investigation. We are already running our own review into workplace culture.
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"It is vital that we have an industry that is not only committed to the highest standards of behaviour and conduct, but that is reflected in people’s experiences.
"We have always been clear that should people want to raise issues with the BBC, they will be taken very seriously.”