Alan Titchmarsh was forced to apologise when the word "t*ts" was used repeatedly on his afternoon show.
The Mirror reports that guests Trinny Woodall and Susannah Constantine used the phrase while discussing lingerie on the programme.
A number of viewers are thought to have complained about the use of language.
"Alan didn't expect them to keep using the word," a source said. "There were a lot of complaints. You could say it was a bit of a boob on their part."
Titchmarsh recently defended a discussion of sex toys on his show.
You can watch the programme on ITV player here: http://www.itv.com/itvplayer/video/?Filter=198719
