“Furthermore, 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 organisations,” the FBI, Cybersecurity and Infrastructure Security Agency and Office of the Director of National Intelligence said in a joint statement.

The agencies did not provide further details on the nature of the stolen material.

Iran has previously denied interfering in US elections.

Iran’s permanent mission to the UN in New York did not immediately respond to a request for comment on Wednesday.

In August, the US accused Iran of launching cyber operations against the campaigns of both US presidential candidates and targeting the American public with influence operations aimed at fanning political discord.

Malicious cyber actors sent unsolicited emails to individuals in Biden’s campaign in late June and early July that contained an excerpt from stolen material from Trump’s campaign as text in emails, according to Wednesday’s statement.

Biden dropped out of the race for the White House on July 21 and was subsequently replaced by Vice President Kamala Harris as the Democratic candidate.

In a statement, the Trump campaign said Harris and Biden should disclose whether they used the hacked material “to hurt” President Trump.

“We’re not aware of any material being sent directly to the campaign,” a Harris campaign spokesperson said in a statement. “A few individuals were targeted on their personal emails with what looked like a spam or phishing attempt.”