Actress Pam Dawber said she was "flashed" and "groped" by Robin Williams on the set of Mork and Mindy, according to a new biography of the late comedian.

Dawber played Mindy, the human woman who befriends the alien Mork (Williams) in the hit Seventies sitcom. "I had the grossest things done to me – by him. And I never took offense," Dawber is quoted as saying in journalist Dave Itzkoff's forthcoming book Robin: The Definitive Biography of Robin Williams.

"I mean I was flashed, humped, bumped, grabbed. I think he probably did it to a lot of people... but it was so much fun," Dawber, 66, continues.

"Somehow he had that magic. If you put it on paper you would be appalled. But somehow he had this guileless little thing that he would do – those sparkly eyes.

"He'd look at you, really playful, like a puppy, all of a sudden. And then he'd grab your t--s and then run away. And somehow he could get away with it. It was the Seventies, after all."