Jailed American Jewish contractor Alan Gross visited Cuba at least five times in one year to set up wireless Internet connections, according to a report citing leaked court documents.

The report Thursday by The Associated Press comes two days after Juan Lamigueiro of the Cuban interests section in Washington posted a letter on the Cuban Foreign Ministry website saying that “the Cuban government has engaged the U.S. government on its willingness to find a humanitarian solution to the case of Mr. Alan Gross on a reciprocal humanitarian basis.” The statement is believed to be referring to the so-called “Cuban Five,” spies arrested in the United States in 1998, which Cuba has been rumored to have asked the U.S. to swap in exchange for Gross.

Gross visited Cuba five times in 2009, the year he was arrested, and his movements there had been tracked since 2004, according to a filing with the court, apparently from Gross’ sentencing, the AP reported. The document was published on the U.S.-based blog Cafe Fuerte, and its authenticity has been neither confirmed nor denied.

The document alleges that Gross recruited other Americans to help bring restricted telecommunications equipment into Cuba.

Gross is serving a 15-year prison sentence in Cuba. He has been jailed since he was arrested in 2009 as he was leaving Cuba.

Gross’ family and U.S. State Department officials say that Gross was in the country on a U.S. Agency for International Development contract to help the country’s 1,500 Jews communicate with other Jewish communities using the Internet. The main Jewish groups in Cuba have denied any contact with or knowledge of Gross or the program.

He reportedly is in poor health and has lost more than 100 pounds.

Gross was not included on a list released last month of nearly 3,000 prisoners whom Cuban leader Raoul Castro said he would release on humanitarian grounds.