Lindsay Lohan is set to make a guest appearance on hit U.s. TV series Ugly Betty.

Rumours surrounding the star's role in the show emerged last week (ends02May08) and suggested she had signed up to eight episodes of the program - but Perez Hilton reports the singer/actress will appear in the show's season finale, after she was photographed on the set of Ugly Betty in Los Angeles on Saturday.

It follows Britney Spears' acclaimed performance on sitcom How I Met Your Mother last month (Apr08) - her guest appearance helped the show earn its highest ever ratings, and she will make a return to the sitcom later this month.