He resigned from the programme when a transcript of comments he had made about contestants was leaked to the public.
The presenter, 52, is now seeking damages from the show.
In November 2022, it was revealed that Mr Walliams had referred to an older performer as a “c---” three times when he was out of earshot after an unsuccessful audition for the ITV talent show.
When a female contestant walked off stage, he also said: “She’s like the slightly boring girl you meet in the pub that thinks you want to f--- them, but you don’t.”
The comments were picked up on his microphone during auditions at the London Palladium in January 2020, and he apologised after they were made public last year.
In a statement at the time, Walliams said: “I would like to apologise to the people I made disrespectful comments about during breaks in filming for Britain’s Got Talent in 2020.
“These were private conversations and – like most conversations with friends – were never intended to be shared. Nevertheless, I am sorry.”
He resigned from the show two weeks later but has now lodged papers at London’s High Court last week accusing BGT’s production company Fremantle of a data protection breach.
Walliams’ comments were picked up by microphones used to capture discussions between the judges, who include Simon Cowell, Alesha Dixon and Amanda Holden.
In a statement last year, ITV said: “We do not condone the language outlined in these allegations, and we have spoken to the producers of Britain’s Got Talent.
“Duty of care towards all participants on any of our programmes is always of paramount importance and we have protocols and guidelines in place for all our production partners.”
Fremantle was contacted for comment.