By Rachel Donadio

New York Times News Service

In 1975, a factory worker at Fiat, the Italian carmaker, bought two colorful paintings for about $70 at an auction in Turin of objects left unclaimed by train passengers. For years, they hung on his kitchen wall. One was a still life with fruit and a small dog; the other showed a woman in white seated in a verdant garden.

Then, last summer, the man’s son, an architecture student, was looking through a book of paintings by Paul Gauguin and saw a familiar image: a still life with a dog. The family called in experts, who contacted the Italian police. On Wednesday, the police said that the paintings were, in fact, a still life by Gauguin from 1889 and “Woman With Two Chairs” by Pierre Bonnard, both of which had been reported stolen from a London home in 1970.

“I’d say it’s quite satisfying,” Gen. Mariano Mossa, the chief of the cultural heritage division of Italy’s paramilitary Carabinieri police, said in a telephone interview after presenting the findings at the Culture Ministry in Rome, following a monthslong investigation.

Mossa said the Gauguin could be worth as much as 35 million euros (around $48 million) and the Bonnard at least 500,000 euros (around $690,000). Auction house experts in New York put the Gauguin’s worth at approximately $15 million and the Bonnard at around $2 million.

Mossa said that the police did not know who had taken the Gauguin and Bonnard paintings from London, but he speculated that they had arrived in Italy on a Paris-Turin train and that whoever was transporting them might have been stopped at customs, abandoning them to the fate of the Italian railroad’s lost property office.

Officials there obviously did not recognize the works, so they sold them, Mossa said. The retired Fiat worker, whose name he declined to disclose, citing continuing investigations, “didn’t understand the value, and he kept them in Turin and then in Sicily after he retired.”

The Carabinieri were able to identify the Gauguin after seeing it in a catalog of Gauguin paintings from 1961, but it did not appear in a 2001 edition of his works.

“That meant it had either been stolen or misplaced,” Mossa said. They found a 1970 article in The New York Times by United Press International that reported the theft of the paintings from a home in Regent’s Park in London.

”The police said that three men posing as burglar-alarm engineers called at 8 Chester Terrace, Regent’s Park,” the report said. ”Two of them started to work on the home’s burglar alarm in the presence of the housekeeper. They asked her to make them a cup of tea, and when she returned, the paintings had been taken from their frames and the men were gone.”

Mossa identified the original owners as Mathilda Marks, a philanthropist and a daughter of Michael Marks, a founder of the Marks & Spencer department-store chain, and Terence Kennedy, an American whom she had married late in life. But he said that neither was alive and that the police had not yet identified an heir.

Rob Singh, a spokesman for Scotland Yard, said that Italian authorities had asked its arts and antiques unit this year for help in tracing the paintings’ owners.

“The unit was able to establish that the paintings were sold by Sotheby’s in the United States in 1962 and advised the Italian authorities accordingly,” he said.