The BBC has reprimanded Graham Norton's chat show for perpetuating "potentially offensive stereotypes" of lesbians.

The corporation upheld a complaint about a show in which the star made comments about a patent application.

Referring to a woman used to illustrate the application, Norton said: "I don't know why they've got some strange lesbian to be the model."

The BBC said a subsequent exchange with guest Ruth Jones could have been seen to reinforce a negative stereotype.

Jones, the star and co-writer of sitcom Gavin and Stacey, scolded Norton, saying: "She may not be a lesbian, come on now."

She went on to say people should not be judged by their appearance, asking the host: "What does a lesbian look like?"

Indicating the illustration, Norton replied: "That."

He also stressed: "Anyway, there's nothing wrong with being a lesbian."

One viewer complained to the BBC about the episode, broadcast on BBC Two in March. The BBC's editorial complaints unit agreed with their comments.

"Although the initial references might have been inoffensive if considered on their own, they prompted an exchange with one of the programme's guests which gave the references the appearance of perpetuating or reinforcing a potentially offensive stereotype," the BBC said.

"The programme team were reminded of the need to avoid any possibility of being seen to endorse offensive sexual stereotypes."

Norton's chat show is set to move to BBC One this autumn.