A bank has publicly apologised after admitting a rogue worker had accessed Italian prime minister Giorgia Meloni’s account.

Intesa Sanpaolo, Italy’s largest bank, said it was “deeply sorry” for the embarrassing security breach, which targeted the accounts of thousands of celebrities, politicians and businessmen.

The Turin-based lender said its systems had identified a “disloyal employee” who was spying on the bank accounts of its customers.

In a statement shared on Sunday, Intesa said: “This must never happen again.”

It notified Italy’s data protection authority, dismissed the employee and filed a complaint as an injured party. However, it said that “there was no cybersecurity issue”.

It comes as the latest twist in a scandal which has gripped Italy amid speculation over whether the breach was linked to efforts to destabilise the government.

The bank clerk accused of spying on 3,500 client accounts is understood to be Vincenzo Coviello. He was based in one of Intesa’s southern Italy branches. Intesa declined to name the employee in its apology.

The 52-year-old allegedly breached customers’ personal accounts more than 6,000 times in the period since February 2022, according to a police investigation.

The affected customers included Arianna Meloni, Ms Meloni’s sister and secretary of the Brothers of Italy party; Raffaele Fitto, Italy’s minister for European Affairs, and the dormant account of Diego Maradona, the late Argentinian footballer.

Mr Coviello told authorities that his actions were motivated by curiosity and frustration with his own career.

The banker said that he did not keep records of banking activity nor shared the information with anyone.

However, Italy’s prime minister faced questions over the weekend about whether the banking breach formed part of a wider conspiracy to undermine her government.

She told the TG5 news programme: “The pressure groups don’t accept having someone in government who doesn’t bend to pressure and can’t be blackmailed. So perhaps they try to get rid of them by other means.

“But I’m afraid they won’t succeed in getting rid of me.”

Ms Meloni also raised the prospect of whether the illegally accessed information had been sold off to a third party.

She said: “We know the phenomenon of thieves who steal jewels from houses and sell them to fences. Well, I think the same thing is happening in the information market.”

Italian politician Tommaso Foti, a senior member of Meloni’s Brothers of Italy party, said the incident was the largest scandal in Italy’s history and questioned whether a “foreign hand” was involved.