At age 87, an architect and professor of art history, Manuel de la Torre, was still fighting to recover the art collection he left behind when he fled Cuba more than four decades ago as an anti-Castro protester after the communist revolution.

Yesterday, two months after his death, members of de la Torre’s family picketed the Upper East Side headquarters of Sotheby’s, repeating claims that the international auction house had attempted to sell one of their prized paintings that had been seized by pro-Castro militants.

The auction house contends it had no idea the painting was allegedly stolen, partly because the de la Torre family did not list it in national art registers as stolen.

The picketing was sparked by the breakdown of settlement talks between the family and Sotheby’s. Absent a settlement, the tangled and lengthy court battle over the ownership of “La Hamaca,” a painting by a Cuban artist who was de la Torre’s friend, Mariano Rodriguez, is likely to continue into the summer.

The protests also marked the second time in recent weeks that Sotheby’s has been publicly accused of auctioning off paintings that had been seized by Cuban communists. On April 30, the auction house announced a settlement agreement with descendants of what was one of the world’s premier sugar-manufacturing families, the Fanjuls, Cuban-Americans now living in Miami. That family claimed its multimillion-dollar art collection was pilfered by pro-Castro militants, later sold abroad, and eventually put up for sale via Sotheby’s.

While Sotheby’s settled with the Fanjuls, members of the de la Torre family, who live on Long Island, expressed disappointment yesterday that they could not reach a similar agreement.

A construction manager for Burger King, Manuel de la Torre Jr., 45, likened Cuban-Americans’ legal struggles to retrieve seized art collections to the efforts of families from Europe to recover assets seized during the Holocaust.

“This case is simple,” he said. “My father’s painting was stolen. Sotheby’s tried to sell it. We want our painting back. All we want is our painting back.”

“La Hamaca” has traveled a torturous path.

In 1971, about 10 years after de la Torre fled Cuba for fear of political im prisonment, his family has said, Castro “goon squads” invaded the home of the exile’s sister-in-law in Cuba and seized several of de la Torre’s 47 prized paintings. That same year, and in a manner that remains unclear, “La Hamaca” was acquired by a Spanish diplomat posted in Havana by the Franco regime, Jesus Navascues.

After Navascues’s death in 1997, the diplomat’s family put the painting, as well as other items, up for auction through Sotheby’s. “La Hamaca” was purchased for $145,000 by a well-known Latin American banker and art collector in New York, Violy McCausland, who four years later looked to resell the painting through Sotheby’s.

Before the 2001 auction, however, de la Torre noticed an image of the painting in a Sotheby’s advertisement placed in the New York Times. The retired architect approached the auction house, saying he was the work’s legal owner. After failing to reach an agreement, de la Torre initiated litigation to retrieve it. The case has been in court ever since.

In response, Sotheby’s canceled the auction of the painting and repurchased it from Ms. McCausland for an undisclosed sum.

Ms. McCausland – a 2003 appointee by Mayor Bloomberg to the city’s Latin Media and Entertainment Commission – could not be reached for comment for this article.

Sotheby’s does not contest de la Torre’s assertion that at one point he owned the painting. Indeed, the auction house cited his prior ownership in promotional material for its 2001 sale. But Sotheby’s contends it cannot be certain that the painting was stolen by pro-Castro goon squads, as de la Torre’s family says, or that it was purchased illegally by the Spanish diplomat, Navascues.

The auction house, however, has also initiated litigation against the Navascues family. If a court declares that the painting does belong to de la Torre’s heirs, a spokeswoman for Sotheby’s, Diana Phillips, said, then Sotheby’s could seek monetary damages from the Navascues family.

An attorney for the de la Torre family, Grant Lally, said settlement talks with Sotheby’s attorneys went into the early morning hours yesterday, but he called the auction house’s terms “oppressive.” Mr. de la Torre Jr. said the auction house was willing to return the painting only on the condition that he and his relatives agree not to discuss the case with representatives of the press, and to allow Sotheby’s to maintain exclusive rights to auction the painting should the family decide to sell it.

Another stipulation, he said, was that his family could not sell the painting in his, or his mother’s, lifetime.

The Sotheby’s spokeswoman, Ms. Phillips, said: “While it is completely inappropriate to discuss confidential settlement negotiations, Sotheby’s has always been willing to settle on reasonable terms.”

De la Torre’s wife, Sylvia, 84, broke down into tears outside the auction house yesterday, remembering the painting that once hung in her dining room and now sits in a location that Sotheby’s declined to divulge. “I can’t understand how this kind of abuse could happen,” she said, through a translator. “This is a painting that belongs to my husband.”

The ownership dispute is pending in state Supreme Court in Mineola, Long Island, before Justice Joseph Covello.