Iranian hackers sent emails containing stolen material from Republican former President Donald Trump’s campaign to people involved in Democratic President Joe Biden’s then re-election campaign, part of an alleged broader effort by Tehran to influence the US election, US agencies have said.

“Iranian malicious cyber actors have continued their efforts since June to send stolen, non-public material associated with former President Trump’s campaign to US media organizations,” the Federal Bureau of Investigation, Cybersecurity and Infrastructure Security Agency, and Office of the Director of National Intelligence said in a joint statement on Wednesday.

“This malicious cyber activity is the latest example of Iran’s multi-pronged approach … to stoke discord and undermine confidence in our electoral process,” the agencies said.

They added that there was currently no information to suggest the recipients replied. They did not provide further details on the nature of the stolen material.

In August, the United States accused Iran of launching cyberoperations against the campaigns of both US presidential candidates and targeting people in the US with influence operations aimed at fanning political discord.

Iran has denied interfering in US affairs.

On Wednesday its permanent mission to the United Nations in New York said the latest US allegations were “fundamentally unfounded, and wholly inadmissible”. It added: “Iran neither has any motive nor intent to interfere in the US election.”

‘Kamala and Biden must come clean’

Malicious cyberactors sent unsolicited emails to individuals in Biden’s campaign in late June and early July that contained a text excerpt from stolen material from the Republican presidential candidate’s campaign, the agencies said.

Biden dropped out of the presidential race on July 21 and Vice President Kamala Harris replaced him as the Democratic candidate. Polls show Trump and Harris are in a tight race.

Karoline Leavitt, Trump’s campaign spokesperson, said the latest allegations were “further proof the Iranians are actively interfering in the election to help Kamala Harris and Joe Biden because they know President Trump will restore his tough sanctions and stand against their reign of terror”.

“Kamala and Biden must come clean on whether they used the hacked material given to them by the Iranians to hurt President Trump. What did they know and when did they know it?” she said in a statement.

A Harris campaign spokesperson said they were “not aware of any material being sent directly to the campaign”.

“A few individuals were targeted on their personal emails with what looked like a spam or phishing attempt.”

The former president claimed in a rally on Wednesday night that Iran hacked into his campaign to help Democrats, calling it foreign election interference.

Tehran also says Washington has interfered in its affairs over decades ranging from a 1953 coup of a prime minister to the 2020 killing of Iranian military commander Qassem Soleimani.