Former FBI agent Robert Levinson is believed to have died in Iranian custody, says his family.
That's based on information from U.S. officials.
Levinson disappeared in March 2007 after traveling to an island - called Kish - controlled by Iran.
President Donald Trump said on Wednesday (March 25) he had not been told that Levinson was dead, but said things weren't looking good.
(SOUNDBITE) (English) US PRESIDENT, DONALD TRUMP:
"No, I don't accept that he's dead. I don't accept it. I'm telling you. It's not looking great but I won't accept that he's dead. They haven't told us that he's dead, but a lot of people are thinking that that is the case."
Despite Trump's remarks, White House national security adviser Robert O'Brien said in a statement later:
"While the investigation is ongoing, we believe that Bob Levinson may have passed away some time ago."
Levinson disappeared after he met with Daoud Salahuddin, an American Islamic militant who fled to Iran while facing charges in the murder of an Iranian embassy official based in Washington.
Sources familiar with his work said Levinson, then a private investigator, was seeking information on alleged corruption - involving former Iranian president Akbar Hashemi Rafsanjani and his family.
The Iranian government has never publicly acknowledged any role in Levinson's abduction.
But at the time of his disappearance a government-affiliated media broadcast a story saying he was quote "in the hands of Iranian security forces."