The presumed mastermind of a brazen art theft from a French Riviera museum involving four paintings by Monet, Sisley and Breughel denied any role as he went on trial on Monday.

The Miami-based Bernard Ternus, who is in his sixties, was sentenced in the United States to five years in prison in 2008 over the theft at Nice's Jules Cheret museum a year earlier.

Transferred to France last year after serving his sentence, Ternus -- who is being held in custody -- told the court in Aix-en-Provence in southern France that he had been framed.