"It appears that while my actual phone device was not breached, access to my Telegram account was indeed gained through various means," Bennett said in a statement late on Wednesday.

"The contents of my contact list, as well as numerous photos and chats -- both authentic and fabricated... have been distributed."

Bennett said the breach was intended to stop him from returning to the premiership.

"Israel's enemies will do everything in their power to prevent me from serving as prime minister again. It will not work," he said.

"No one will stop me from acting and fighting for the state of Israel and the people of Israel."

The Times of Israel reported that material taken from Bennett's account was published on a website allegedly operated by the Iran-linked Handala hacker group.

The group claimed to have left a message on Bennett's phone, which it published on its website.

"Dear Naftali Bennett. You once prided yourself on being a beacon of cybersecurity, parading your expertise before the world," it said on the website.

"For all your boasts and bravado, your digital fortress was nothing more than a paper wall waiting to be breached."

The daily Haaretz carried out checks and confirmed that many of the phone numbers are authentic and belong to senior officials in Israel and abroad -- among them, members of the government, as well as senior officials and international leaders.

Before entering politics, Bennett had co-founded a device protection software and an online security company.

Iran's official IRNA news agency published the names of contacts obtained from Bennett's account, but did not say whether the hackers were linked to Iran.

Bennett has declared his intention to run for prime minister in the next parliamentary elections due in October 2026, in a bid to oust Prime Minister Benjamin Netanyahu.

Bennett first served as prime minister from June 2021 to June 2022 in a coalition of right-wing, left-wing and centrist parties that unseated Netanyahu.

That government collapsed a few months later, paving the way for Netanyahu's return.