Prosecutors in Poland have opened an investigation into reports that a Swedish artist used ashes from the Nazi death camp at Majdanek in a painting, BBC News reported.

Carl Michael von Hausswolff's picture was hanging in a gallery in the Swedish city of Lund until protests caused the exhibition to close last month.

Von Hausswolff said he had collected the ashes from the crematorium at Majdanek during a visit in 1989.

The prosecutors said they had still no evidence a crime had been committed.

If the artist is charged with desecrating human ashes, he could face up to eight years in prison.

It is estimated the Nazis murdered 80,000 people at Majdanek, three-quarters of them Jews, during the German occupation of Poland in World War II.