A French thief already convicted in Switzerland for stealing dozens of valuable artworks has gone on trial in Strasbourg, eastern France.
Breitwieser claimed to be an enthusiastic collector
Stephane Breitwieser, 33, has admitted stealing 239 artworks - including priceless masterpieces - in seven European countries in 1995-2001.
He claims a love of art motivated him. He was given a four-year jail sentence in Switzerland in February 2003.
He was extradited last year to face charges for 20 works stolen in France.
For years Stephane Breitwieser scoured European museums, pilfering works which he hid in his rucksack or inside his coat, then simply walked out, the AFP news agency reports.
He was arrested in November 2001 near the Richard Wagner Museum in Lucerne, Switzerland.
The wine waiter admitted having removed canvases by Watteau, Boucher and Durer from their frames - and the masterpieces have never been recovered.
His thefts allegedly took place in France, Belgium, the Netherlands, Germany, Austria and Switzerland.
His mother, Mireille Stengel, is also on trial for having destroyed more than 200 works stolen by her son, who had stored them at her home in Eschentzwiller, eastern France.
She admitted having cut up canvases "to punish her son," who she alleged had "terrorised" her.
About 100 antiques, including vases and incense-burners, were recovered from the Rhine-Rhone canal after his arrest.
But up to 60 paintings have not been found.