"I've only stolen what interested me for my collection," Breitwieser told a court in eastern Strasbourg, where he is standing trial for stealing 23 works of art in France, Austria and Denmark.
Breitwieser, who was arrested in Switzerland after a theft at Lucerne's Richard Wagner Museum in November 2001, was sentenced to four years in jail by a Swiss court in February 2003 for having stolen 69 works in that country.
He was extradited to France in July 2004.
"I think Mr Breitwieser will enter into the record books not only for the theft but also for the destruction of artworks," said Bernard Darties, head of France's central office for the fight against traffic in cultural goods.
Breitwieser's mother is accused of throwing some artworks into the Rhine-Rhone canal near their home in Mulhouse and of putting others out for the rubbish collectors after her son's arrest. About a hundred artworks were fished out of the canal.
Mireille Stengel, 53, told investigators she wanted to "punish" her son by destroying what was most dear to him.
She and Breitwieser's ex-girlfriend, Anne-Catherine Kleinklaus, face charges of handling stolen goods.
Breitwieser has always declared he was stealing out of "love of art" and did not aim to make a profit from it.
He told the court he had tried to "restore" many of the art works he stole. Only 112 of the 240 stolen objects have been found, many of them broken or damaged.
From his prison in Switzerland, Breitwieser wrote to some of the museums from which he had taken objects, offering suggestions on how to improve their security.
"The distracted guard, either absent or asleep on his chair" was often their weakness, he told the Swiss court.