Hundreds of unknown Pablo Picasso works worth tens of millions of euros have surfaced in France in the hands of a 71-year-old retired electrician who says they were gifts from the master.

Dating from the first third of the 20th century — considered Picasso’s most fertile period — the 271 pieces are valued by experts at more than 60 million euros.

And the new-found drawings, paintings and studies are now at the heart of a legal tug-of-war between the electrician, Pierre Le Guennec, and the artist’s heirs who believe they must have been stolen and have filed for charges.

“No one can seriouly believe that the artist made these gifts, it’s completely crazy,” the Picasso family’s lawyer Jean-Jacques Neuer told AFP on Monday.

“This electrician, who claims to have been a long-time friend, has never been heard of despite the fact we now know every detail about Picasso’s life.”

The Picassos all date from between 1900 and 1932 — from the artist’s years as a struggling youth freshly arrived in France from Barcelona, up until the first major retrospectives of his work.

Treasures in the collection include nine extremely fragile cubist collages — alone believed to be worth some 40 million euros — as well as a watercolour from the Spanish master’s so-called Blue Period.

There are also more than 200 drawings, among them several portraits of Picasso’s first wife, Olga, as well as 15 studies for his 1925 work “The Three Graces,” and subjects ranging from a dog fight to a crucifixion.

Le Guennec says he worked installing alarm systems at several of Picasso’s residences, including a villa in the Riviera city of Cannes, during the three years up until the artist’s death in 1973.

He said he was given all of the works, either by Picasso’s late wife or by the artist himself.

Interviewed on French radio RTL Monday, Le Guennec insisted the works were freely donated — while downplaying the scale of the collection.

“The master and madam made a gift to me. They gave them to me, as they might have given anything else,” he said. “They’re not paintings — or I would have needed a truck. It’s a few drawings and sketch fragments, that’s all.”

“I’m aware they must be worth something — but I wasn’t interested in that. If I was I would have tried to sell them long ago,” he said.

He said he came forward with the works after a spell of ill-health, for fear his children would have trouble accounting for them.

But Picasso’s heirs dispute the claim, not least because the artist was known to jealously guard his own works, often proving reluctant to sell and sometimes even buying back favoured pieces from which he had been separated.

And those gifts which Picasso did make were always signed, they claim.

“Frankly it just doesn’t stand up,” Claude Picasso, the artist’s son and the administrator of his estate, told Liberation. “This was a part of his life.”

Picasso’s son was first alerted in January when he received 26 photographs of works purported to be by his father, sent to him by Le Guennec.

Along with the poor quality pictures, he received a letter asking him to authenticate the works. Another set of 39 images followed a few months later.

Claude Picasso refused, only to receive a visit in September at his Paris offices from the elderly Le Guennec couple, who turned up with a suitcase packed with 175 works by the master, including two notebooks containing 97 drawings — none of which figure in official inventories of the artist’s work.

Once experts had authenticated all the works, Picasso’s heirs filed suit on September 23 for dealing in stolen goods.

The entire collection was impounded from the couple’s Riviera home two weeks later and is being held in a secure vault near Paris by the French office for the prevention of artwork trafficking, OCBC, which confirmed the seizure to AFP.

Le Guennec was briefly held for questioning but neither he nor his wife have so far been charged in the case, his lawyer Evelyne Rees told AFP Monday.

“Mr Le Guennec says that if he was dealing in stolen goods, he would hardly have walked straight into the lion’s den,” by contacting the artist’s heirs, she said.