GENEVA (AFP) - Swiss police confirmed on Tuesday they were investigating rape allegations against Roman Polanski made by a woman who said the director assaulted her in 1972.

St Gallen police communications chief Krusi Hanspeter said police interviewed Renate Langer on Sept 26 concerning claims that she was raped when she was 15.

Polanski in 1977 pleaded guilty in the United States to having unlawful sex with Samantha Geimer - aged 13 at the time - but fled from the country before he could be sentenced.

Langer, a 61-year-old former actress, is the fourth woman to publicly accuse Polanski of sexual assault.

In August, a woman identified only as Robin told a news conference in Los Angeles she was "sexually victimised" by the French-Polish director when she was 16, in 1973.

Robin said she was prompted to come forward after Geimer urged authorities to finally put her famous case to rest.

Robin told reporters she wanted people to know that Polanski, now 84, had victimised others.

According to The New York Times, Langer finally decided to approach the police in part because of Robin's example and because her parents are no longer alive.

She told the paper she met Polanski while working as a model in Munich and travelled with him to a house in Gstaad, where she said he raped her.

Mr Hanspeter said it was not yet clear if criminal charges would be filed.

Swiss prosecutors can still move forward with the case although the elapsed time makes it less likely.