Ambitious About Autism has now announced it is “no longer working with” the 60-year-old TV host “in light of recent allegations”.
“We have let him know our decision and thanked him for his support of our work over the last two years,” it said in a statement.
Wallace has three children and his youngest, five-year-old Sid, is non-verbal and autistic.
The presenter is yet to directly address any of the allegations but after his MasterChef exit was announced, he posted a short Instagram video thanking “all the people getting in touch [and] showing their support”.
The star’s lawyers say “it is entirely false that he engages in behaviour of a sexually harassing nature”, BBC News reported.
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Sky News has contacted Wallace’s representative for comment.
The complaints are being investigated by MasterChef’s production company Banijay UK.
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Newsnight presenter Kirsty Wark was among a number of women who have spoken out about Wallace’s alleged behaviour this week.
In an interview with the BBC, Wark claimed she saw Wallace “use sexualised language in front of a number of people” when she appeared on Celebrity MasterChef in 2011.
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Gregg Wallace declines to comment
In light of the allegations, singer Sir Rod Stewart criticised Wallace on Instagram and claimed he “humiliated” his wife Penny Lancaster in 2021.
He wrote: “Good riddance Wallace… You humiliated my wife when she was on the show, but you had that bit cut out didn’t you?
“You’re a tubby, bald-headed, ill-mannered bully.”
A representative for Lancaster has now told Sky News: “While Penny is happy to talk to the appropriate authorities should they feel she has anything useful to add, she will not be discussing this matter with any broadcaster or newspaper at this time.”