New Ben Affleck sexual assault claims surface

A makeup artist has alleged she was sexually assaulted by Hollywood actor Ben Affleck, just hours after a video resurfaced of him appearing to grope a MTV presenter's breast.

Earlier on Thursday (local time), the Argo star apologised and admitted he "acted inappropriately" with former MTV VJ Hilarie Burton during filming of Total Request Live in 2003.

But now Annamarie Tendler, the wife of prominent US comedian John Mulaney, says she wants Affleck to say sorry to her too.

"I would also love to get an apology from Ben Affleck who grabbed my ass at a Golden Globes party in 2014," she wrote.

"He walked by me, cupped my butt and pressed his finger into my crack."

Tendler says Affleck then tried to play the alleged sexual assault off as an accident.

"I guess he tried to play it like he was politely moving me out of the way and oops touched my butt instead of my lower back?" she explained.

"Like most women in these situations I didn't say anything, but I have thought a lot about what I'd say if I ever saw him again."

Allegations have started coming in after Affleck denounced the actions of embattled film executive Harvey Weinstein.

The movie mogul has been sacked by the board of his hugely successful Weinstein Company, and suffered a very public fall from grace in the wake of a bombshell New York Times report that exposed an allegedly extensive history of sexual harassment.

In a rousing post, Affleck condemned Weinstein for "using his position of power to intimidate, sexually harass and manipulate women over many decades", claiming the allegations "made [him] sick".

He also made a call for men to "do better" at empowering women and protecting them from sexual harassment, urging them to criticise such behaviour when it's noticed.

However, his remarks have come back to bite him, with several Twitter users calling him a hypocrite and bringing attention to both his brother Casey's alleged sexual harassment and his own groping of Burton 14 years ago.

"He also grabbed Hilarie Burton's breasts on TRL once. Everyone forgot though," one user wrote, before being corrected by Burton herself.

On the original segment, Burton laughed off the grope, joking that she'd "rather have a high-five" - but in a series of tweets explained she was "just a kid" and "had to laugh back then so I wouldn't cry".

Affleck, in response, offered his "sincerest apologies" to Burton and admitted he "acted inappropriately".