The FBI is investigating allegations that sensitive documents from Donald Trump’s presidential campaign were stolen in a cyber intrusion, as well as attempts to gain access to Vice President Kamala Harris’ campaign, days after the Trump campaign declared it had been hacked by Iran.

The FBI released a brief statement on the Trump matter reading, “We can confirm the FBI is investigating this matter.”

The Trump campaign provided no specific evidence of Iran’s involvement, but the claim came shortly after Microsoft issued a report detailing foreign agents’ attempts to interfere in the US election in 2024.

The report cited an instance of an Iranian military intelligence unit in June sending “a spear-phishing email to a high-ranking official of a presidential campaign from a compromised email account of a former senior advisor.”

Two people familiar with the matter said the Biden-Harris campaign was also targeted in the suspected Iranian cyber intrusion that is under FBI investigation.

The people spoke on the condition of anonymity because they were not authorized to discuss the details of the investigation.

Politico reported Saturday that it began receiving emails on July 22 from an anonymous account.

The source — an AOL email account identified only as “Robert” — passed along what appeared to be a research dossier the campaign had apparently done on the Republican vice presidential nominee, Ohio Sen. JD Vance.

The document was dated Feb. 23, almost five months before Trump selected Vance as his running mate.

“These documents were obtained illegally” and “intended to interfere with the 2024 election and sow chaos throughout our Democratic process,” Trump campaign spokesperson Steven Cheung said.

At least three staffers in the Biden-Harris campaign were targeted with phishing emails, but investigators have uncovered no evidence the attempt was successful, one of the people said.

The attempts came before President Joe Biden dropped out of the race.

The FBI began investigating that cyber incident in June and intelligence officials believe Iran was behind the attempts, that person said.

Officials have also been in touch with tech companies in recent months about the possibility that people linked to the Trump and Biden-Harris campaigns were being targeted through email.

Harris’ campaign said in a statement, “Our campaign vigilantly monitors and protects against cyber threats, and we are not aware of any security breaches of our systems.”

It declined to address whether it had identified any state-based intrusion attempts.

Iran’s mission to the United Nations, when asked about the claim of the Trump campaign, denied being involved.

However, Iran long has been suspected of running hacking campaigns targeting its enemies in the Middle East and beyond.

Tehran also long has threatened to retaliate against Trump over the 2020 drone strike he ordered that killed prominent Revolutionary Guard Gen. Qassem Soleimani.

In its report, Microsoft stated that “foreign malign influence concerning the 2024 US election started off slowly but has steadily picked up pace over the last six months due initially to Russian operations, but more recently from Iranian activity.”

The analysis continued: “Iranian cyber-enabled influence operations have been a consistent feature of at least the last three US election cycles. Iran’s operations have been notable and distinguishable from Russian campaigns for appearing later in the election season and employing cyberattacks more geared toward election conduct than swaying voters.”

“Recent activity suggests the Iranian regime — along with the Kremlin — may be equally engaged in election 2024,” Microsoft concluded.