In early January 2017, when the Cuban government was looking for insights into the newly elected President Donald Trump, his former campaign chief, Paul Manafort, traveled to the island to meet with “Castro’s son,” according to a U.S. Senate report.

The recently released Senate Intelligence Committee report on Russia’s interference in the 2016 presidential election states that Manafort claimed the meeting was arranged by Brad Zackson, the former exclusive broker for the properties of Trump’s late father, Fred Trump.

Manafort left the Trump campaign in August 2016, mired in scandal over his undisclosed work as a lobbyist for a pro-Russian political party in Ukraine. As a result of special counsel Robert Mueller’s investigation into the Trump campaign’s ties to Russia, Manafort was sentenced to more than seven years in prison for tax and bank fraud. He is currently serving his sentence under house arrest.

But in early January 2017, Manafort did not know that the FBI was investigating him.

On Jan. 15, just days before Trump’s inauguration, Manafort emailed Kathleen T. McFarland, about to be confirmed as the deputy national security adviser in the new administration, the Mueller report says.

“I have some important information I want to share that I picked up on my travels over the last month,” wrote Manafort, who later told the FBI that the email, never answered by McFarland, had to do with Cuba.

The Senate report adds that Manafort told the FBI that the email was related “to an effort that Manafort undertook with Brad Zackson, who had arranged a meeting between Manafort and ‘Castro’s son’ in Havana.” The report refers to a redacted source, “showing Manafort and Zackson on same flight booking to Havana.”

A sentence in the Mueller report offers the only detail about the trip’s possible dates: “On January 8, 2017, hours after returning to the United States from a trip to Cuba, Manafort flew to Madrid, Spain.”

It is not clear if the meeting with one of the Castros ever took place nor his intentions for visiting a country under a U.S. embargo. Neither Manafort’s attorneys nor Zackson responded to questions sent by the Miami Herald. But the Mueller report notes that after Trump’s victory, Manafort said he preferred not to take a job in the new administration and “monetize his campaign position to generate business given his familiarity and relationship with Trump.”

“Manafort appeared to follow that plan, as he traveled to the Middle East, Cuba, South Korea, Japan and China and was paid to explain what a Trump presidency would entail,” the report adds.

The timing of the Cuba trip seemed about right. Worried about the prospects of the fragile “thaw” sought by President Barack Obama, Cuban officials began to discreetly communicate with their contacts in the United States to understand what Trump might do about Cuba and how to get his ear.

The Intelligence Committee report does not clarify the identity of “Castro’s son,” but it is most likely Col. Alejandro Castro Espin, the son of former President Raul Castro. Castro Espin was in charge of the secret negotiations with the Obama administration to exchange prisoners and reestablish diplomatic relations.

The sons of Fidel Castro, who died in 2016, do not have such political influence, although one, Antonio Castro, is known for his lavish lifestyle and foreign connections.