A former FBI agent who mysteriously vanished in 2007 died in Iranian custody, his family concluded Wednesday, saying US intelligence had made them give up 13 years of hope.

President Donald Trump did not confirm Bob Levinson's death, saying that Iran had not communicated any news on the former agent, who would have turned 72 this month.

But Levinson's family said that it had learned that he was dead, although it gave no information on how or when.

"We recently received information from US officials that has led both them and us to conclude that our wonderful husband and father died while in Iranian custody," the family said in a statement.

"We don't even know when, or even if, his body would be returned to us. This is the very definition of cruelty."

The family said Levinson died before the coronavirus pandemic, which has hit Iran hard and led authorities to release thousands of prisoners temporarily. Levinson is one of a number of Americans who have disappeared in arch-­enemy Iran, but his case has been among the most perplexing, with his family until now insisting he was alive.

The father of seven vanished in March 2007 in Kish, and was said to have been investigating cigarette counterfeiting.

But The Washington Post reported in 2013 that Levinson, who had retired from the FBI, was working for the CIA and had gone on a rogue mission aimed at gathering intelligence on Iran. It said at the time that the CIA paid $2.5 million to Levinson's wife Christine, accepting responsibility for his disappearance.