David Walliams and Alesha Dixon have reportedly clashed over his 'Little Britain' past.
The 'Britain's Got Talent' judges had an on-set disagreement over the comedy show, with Alesha apparently describing the characters as "inappropriate".
A TV insider told The Sun newspaper: "She is becoming more determined to use her platform for good and speak out where she feels she should.
"It kicked off after the deliberation stages of putting one of the acts into the final.
"When the artist who Alesha had backed got through she basically turned to David and said, 'Well that's payback for all your inappropriate 'Little Britain' antics'.
"It was quite catty, although Alesha later insisted she was only joking. But David was stunned. Obviously he is not racist or homophobic, or anything-phobic in the slightest - he was upset.
"Words were exchanged, and the rest of filming was pretty awkward. He didn't hang around after, and was the first judge to leave."
A source close to Alesha, 41, insisted her comments were made in jest.
And despite the comments, the celebrity duo remain good friends.
The insider said: "They are professionals, and will clearly turn it on for the cameras.
"Alesha is adamant she was only joking, so it's water under the bridge as far as she is concerned. It's back to business as usual for David too. He's not one to hold grudges."
In June, Matt Lucas - David's 'Little Britain' co-star - apologised for playing "characters of other races" in the comedy series.
He said: "David and I have both spoken publicly in recent years of our regret that we played characters of other races.
"Once again we want to make it clear that it was wrong and we are very sorry."