MasterChef producers have appointed a “rigorous” law firm to lead an investigation into the alleged misconduct of presenter Gregg Wallace.

It comes after a BBC News investigation heard allegations of inappropriate sexual comments and inappropriate behaviour by 13 people who worked with Wallace across a range of shows over a 17-year period.

We put the claims to Wallace’s representatives on Tuesday.

On Thursday, MasterChef’s production company Banijay UK said Wallace would step away from presenting the show while allegations of historical misconduct were investigated.

The 60-year-old is “committed to fully co-operating throughout the process”, Banijay added.

Wallace’s lawyers say it is entirely false that he engages in behaviour of a sexually harassing nature.

On the appointment of London law firm Lewis Silkin, a Banijay UK spokesperson said it was a “highly experienced specialist investigations team which has overseen a broad range of high-profile workplace investigations”.

“Banijay UK has been impressed by the firm’s rigorous, in-depth, and impartial analysis and reporting,” they added.

“All information will be handled sensitively, and names of those providing evidence to the team will be kept confidential.”

Announcing its investigation on Thursday, Banijay UK said in a statement: “This week the BBC received complaints from individuals in relation to historical allegations of misconduct while working with presenter Gregg Wallace on one of our shows.”

In a video posted Instagram that evening, Wallace said: “I would like to thank all the people getting in touch, reaching out and showing their support.

“It’s good of you – thank you very much.”

Warning – this article contains distressing content

Veteran broadcaster Kirsty Wark was one of the 13 people who spoke to the BBC about Wallace. She was a Celebrity MasterChef contestant in 2011.

Wark said on two occasions during early morning filming, Wallace told stories and jokes of a “sexualised nature” in front of contestants and crew.

BBC News also heard from a former MasterChef worker who says Wallace showed her topless pictures of himself and asked for massages.

A former worker on Channel 5 show Gregg Wallace’s Big Weekends says he was fascinated by the fact she dated women and asked for the logistics of how it worked.

Other claims made to BBC News include:

• A female worker on MasterChef in 2019, who said Wallace talked about his sex life and asked her if her new boyfriend had a nice bottom
• A female worker on the BBC Good Food Show in 2010, who said Wallace stared at her chest
• A female worker on Eat Well For Less in 2019, who said Wallace told her he wasn’t wearing any boxer shorts under his jeans
• A male worker on MasterChef in 2005-06, who said Wallace regularly said sexually explicit things on set. He said Wallace once said a dish tasted like his aunt’s vagina, and on another occasion, asked a female runner if she put her finger up her boyfriend’s bottom
• A male worker who worked on Big Weekends and other travel shows between 2019 and 2022, who says Wallace talked about threesomes with prostitutes and said he “loves spanking” multiple times a day

A BBC spokesman said: “We take any issues that are raised with us seriously and we have robust processes in place to deal with them.”

Last month, the BBC also announced an independent review of its workplace culture.

A spokesman for Channel 5, which airs Big Weekends, said: “We take any allegations of this nature extremely seriously.

“We have asked the production company to look into these historical claims. The health and wellbeing of everyone involved in our productions is very important to us and we want all of our productions to be safe and secure places for people to work.”

Production company Rumpus, which produced Big Weekends, said: “We do not tolerate inappropriate behaviour on our productions.

“Our comprehensive duty of care processes were in place during production of these series and any matters raised would have been investigated in accordance with these.”