LOS ANGELES - Model-actress Emily Ratajkowski has accused singer Robin Thicke of sexually assaulting her on the set of the music video for his 2013 hit Blurred Lines.

In her upcoming book, My Body, Ratajkowski, 30, alleged that Thicke had groped her bare breasts from behind her.

British newspaper The Sunday Times reported on Sunday (Oct 3) that Ratajkowski claimed that Thicke, 44, returned to the set a little drunk to shoot just with her.

In the music video, she and two other near-naked models appeared alongside Thicke, as well as singer Pharrell Williams and rapper T.I.

The Gone Girl (2014) actress wrote: "Out of nowhere, I felt the coolness and foreignness of a stranger's hands cupping my bare breasts from behind. I instinctively moved away, looking back at Robin Thicke."

Thicke, now a judge on reality show The Masked Singer, has yet to respond to the allegations, which were corroborated by the video's director, Diane Martel.

Martel said she recalled the alleged incident on the all-female set: "I remember the moment that he grabbed her breasts. One in each hand. He was standing behind her as they were both in profile."

The director said she yelled at Thicke, who later apologised.

Ratajkowski, who wanted to minimise the incident and continue with the shoot as a professional, said: "I pushed my chin forward and shrugged, avoiding eye contact, feeling the heat of humiliation pump through my body. I didn't react - not really, not like I should have."

In her book, out on Nov 9, she wrote that she did not dwell on the alleged incident until she realised that Thicke had blocked her on Instagram.

"With that one gesture, Robin Thicke had reminded everyone on set that we women weren't actually in charge," she said of the alleged incident. "I didn't have any real power as the naked girl dancing around in his music video. I was nothing more than the hired mannequin."

Blurred Lines topped charts around the world after its release, but its lyrics and music video have been criticised by some who claimed they referred to non-consensual sex, although Thicke denied it.