The César Awards, France's equivalent of the Oscars, saw demonstrations and walk outs on Friday night after Roman Polanksi won best director.

The 87-year-old was convicted of the statutory rape of a 13 year old in 1977 in the US and is the subject of several other rape allegations.

Crowds gathered outside the event in Paris, holding placards and chanting against the Awards' recognition of Polanksi.

The director was expelled by the Oscars Academy in 2018 "in accordance with the organisation’s standards of conduct."

The 87-year-old won best director. Credit: AP

Protesters then marched toward the Champs Elysees and Arc de Triomphe before being stopped by police firing tear gas.

Inside the awards ceremony, several stars marched out when the French-Polish filmmaker won the award for best director.

Polanksi's new film J’accuse, in English "An Officer and a Spy", received twelve nominations for France's highest film honour.

Demonstrators protested against Polanksi's recognition at the awards. Credit: AP

Footage posted by French television channel Canal+ shows actress Adèle Haenel marching out of the event when Polanski was announced the winner.

A second French actress, Noemie Merlant, also left the ceremony.

Polanski had initially intended to attend the 45th ceremony of Césars, but failed to attend the event saying he was afraid he would face a "public lynching".

French culture minister Franck Riester has since reportedly waded in saying that to give Polanski an award would send the wrong signal.

Women's rights activists had called for a boycott of the Césars ceremony in Paris.

The entire male-dominated leadership of the awards stepped down recently amid a spat over its decision-making structure and over how to deal with the Polanski problem.

Now based in France, Polanski is still wanted in the United States - decades after he was charged with raping a 13-year-old girl in 1977 before he then fled.