Republican Donald Trump and his allies are suggesting that rival Hillary Clinton’s emails may be responsible for the death of an Iranian nuclear scientist who was executed for spying for the United States, even though there is no credible evidence of any such link. Some emails released by the State Department that had passed through Clinton’s homebrew server appeared to reference the scientist, Shahram Amiri.

Trump is using the “people are saying” sentence structure he often favors to make accusations:

“Many people are saying that the Iranians killed the scientist who helped the U.S. because of Hillary Clinton’shacked emails,” he tweeted Monday night.

Trump’s vice presidential candidate, Mike Pence, said “it’s absolutely essential that we get to the bottom of this.”

It would be “heartbreaking,” Pence said on “The Sean Hannity Show” Monday, if someone who had cooperated with the United States, “lost their life because of the recklessness and the carelessness of Hillary Clinton using a private server.” He added that none of that is clear, but “the American people have the right to know.”

Former New York Mayor Rudy Giuliani, a prominent Trump supporter, doubled down on the claim Tuesday as he introduced Trump at a rally in Wilmington, North Carolina. Accusing Clinton of lying and being “extremely careless.”

Iran executed Amiri this week for spying for the United States, acknowledging for the first time that the nation secretly detained and tried a man who was once heralded as a hero.

The emails released by the State Department provide information similar to what U.S. officials had already discussed publicly at the time.

“There was public reporting on this topic back in 2010,” State Department spokeswoman Elizabeth Trudeau said. “Former Secretary Clinton discussed this issue in public at that time. So, this is not something that became public when the State Department released those e-mails.”

The FBI has said it was possible foreign hackers gained access to Clinton’s personal email account. It found no evidence that Clinton’s server was hacked when she was secretary of state, although the FBI director said if it had been hacked investigators probably would not be able to detect any evidence of such a break-in.

Tweeted back Clinton spokesman Nick Merrill:

“‘Many people are saying’=’I made this up.'”

Merrill added that after Trump’s morning speech to the Detroit Economic Club – and sticking closely to his script – “the muzzle was bound to come off.”

Trump’s speech was designed in part to reassure Republicans unnerved by a disastrous week of self-inflicted feuds with an assortment of people, from grieving Muslim American parents to the leaders of his own party.

Amiri first vanished in 2009 while on a religious pilgrimage to Muslim holy sites in Saudi Arabia, but resurfaced a year later in a series of contradictory online videos filmed in the U.S. He then walked into the Iranian-interests section at the Pakistani Embassy in Washington and demanded to be sent home.

When he returned to Iran in 2010, he was given a hero’s welcome and greeted with flowers by government leaders. Then he mysteriously disappeared. Iranian officials said this week that he was tried in a death-penalty case that was upheld by an appeals court.

Amiri’s case indirectly found its way into the spotlight last year with the release of State Department emails sent and received by Clinton. U.S. officials already had discussed his case publicly in 2010, including a $5 million payment offered to him if he stayed in the U.S.

One email forwarded to Clinton by senior adviser Jake Sullivan on July 5, 2010 – just 10 days before Amiri returned to Tehran – appears to reference the scientist.

Clinton’s decision to store her emails on a private server in her New York home sparked an FBI investigation and has become a dominant issue in the presidential campaign. The FBI declined to prosecute her.