Lars Von Trier has caused a stir in Cannes by calling himself a Nazi.

The director stunned onlookers at a press conference for his latest film 'Melancholia' at the film festival in the south of France by making provocative comments about the extremist party.

Alluding to his German heritage, he said: "I thought I was a Jew for a long time and was very happy being a Jew ... Then it turned out that I was not a Jew ... I found out that I was really a Nazi which also gave me some pleasure."

He also joked that he was in the process of writing a four-hour-long hardcore porn film featuring 'Melancholia' stars Kirsten Dunst and Charlotte Gainsbourg, containing "a lot of very, very unpleasant sex".

Meanwhile, Kirsten looked on aghast and tried to restrain his comments by putting her arm on his shoulder.

If Lars was trying to attract more attention to his film there was no need, as the picture has received high praise from critics.