MILAN, Oct 14 (Reuters) - Italy's biggest bank Intesa

Sanpaolo is under investigation by prosecutors in the

southern city of Bari following a security breach caused by a

former employee, Italian news agency ANSA reported on Monday.

On Sunday, the bank apologised after a former employee had

spied on the bank accounts of thousands of customers, including

Prime Minister Giorgia Meloni.

Intesa, which fired the employee, declined to comment.

Under Italian law, a company is held liable for a number of

alleged offences committed by its officials. However, being

under investigation does not necessarily mean it will end with a

trial or a finding of guilt.

According to ANSA, Bari prosecutors considered investigating

the bank because they suspected it of failing to promptly report

abusive cyber-accesses by its employee, who is under

investigation for abusive access to computer systems and

attempted theft of information concerning state security.

After news of the investigation emerged, lawyers for some of

the customers who were victims of the alleged spying requested

information from the prosecutors ahead of possible damages

suits, ANSA reported.