Pierre Le Guennec, who was Picasso's handyman, and his wife, Danielle, were convicted last year of possession of stolen goods and given a two-year suspended prison sentence.
At an appeal hearing in Aix-en-Provence Le Guennec changed his story.
At the earlier trial he said he had been given the works in 1971-72, when Picasso was still alive.
Picassos in rubbish bags
At Monday's hearing he said the artist's widow, Jacqueline, had asked him to store the 15-17 rubbish bags full of artworks after Picasso's death in April 1973.
He did not tell the truth at his earlier trial for fear of "being accused, along with Madame, of stealing" the bags' contents, he told the court, adding that Jacqueline may have been trying to conceal the works from an estate inventory due to "problems she was having" with her stepson, Claude.
He said she later retrieved the bags but gave him one - containing 271 works including collages, sketches and "crumpled paper" - as a gift.
A lawyer for the Picasso family, Jean-Jacques Neuer, denounced the testimony as a "staggering lie" and said the electrician had taken advantage of two elderly people.
A verdict is due on 16 December.