A duo who tried to fence a stolen Matisse masterpiece this summer to FBI undercover agents in Miami Beach have pleaded guilty in federal court.

Pedro Antonio Marcuello Guzman, 46, of Miami, and Maria Martha Elisa Ornelas Lazo, 50, of Mexico City, attempted to sell “Odalisque in Red Pants,” which was stolen from a Venezuelan museum a decade ago.

On Tuesday, Marcuello pleaded guilty to conspiring to transport and sell stolen property and related charges, and Ornelas pleaded guilty to one conspiracy charge. He faces up to 10 years in prison and she up to five years at their sentencing, set for Jan. 22 before U.S. District Judge Donald Middlebrooks.

According to court records, FBI undercover agents posing as buyers tracked down the Henri Matisse painting — valued at $3.7 million — and made arrangements to buy it from the pair. Ornelas brought the 1925 masterpiece through Miami International Airport to a hotel in Miami Beach in July.

The missing painting had been swapped for a forgery at the Caracas Contemporary Art Museum. The museum purchased the piece in 1981 for more than $400,000. It was on loan for a short time to a Spanish exhibit in 1997.

In December 2002, the museum reported it stolen. A few months later, museum leaders told the public about the theft.

While the theft itself remains unsolved, Marcuello told the FBI it was an inside job, supporting museum director Rita Salvestrini suspicions that the painting was taken by someone with access to the museum.

Investigators from Venezuela, Spain, France, Britain, Interpol and the FBI pursued an array of leads, according to published reports.

A Caracas newspaper suggested the swap happened during the loan in Spain. The Associated Press said French police were investigating a lead that the painting was taken to Matisse’s home country.

The AP also reported the FBI suspected the painting was taken by a Venezuelan woman living in Miami Beach, who stored the painting in Miami before smuggling it to Spain.

Marcuello told an FBI agent that a friend had tried to sell the painting in Spain, but the sale fell through when the parties couldn’t agree on a price. It didn’t say whether the painting was in Spain during the time of the arranged sale.

The piece found its way to Ornelas’ home in Mexico City, where she looked up the painting online to see what she was dealing with. Her husband is one of Marcuello’s “main associates,” Marcuello told the FBI.

After an agent met with Marcuello, he arranged for Ornelas to get a visa, hop on a plane and come to Miami with the painting. She carried the multi-million-dollar artwork through customs at MIA.

After a few meetings at a coffee shop and a Miami Beach restaurant, the two agents made arrangements to meet in a room at the Loews Hotel in Miami Beach to purchase the painting from Marcuello and Ornelas.

Agents arrested the duo at the hotel.