Milan's chief prosecutor says the charismatic founder of an Italian party that had vowed to fight political greed is himself under investigation in a widening embezzlement scandal involving party funds.

Prosecutor Edmondo Bruti Liberati said in a statement Wednesday that Umberto Bossi has been formally notified he is under investigation along with his sons, Renzo and Riccardo.

Bossi quit as leader of the Northern League last month after the scandal emerged but denied personal use of party funds.

Bossi was the main partner in all three conservative governments led by Prime Minister Silvio Berlusconi since the 1990s.

The anti-immigrant Northern League, based in the affluent north, has long railed against what it contends is Rome-based political corruption. Prosecutors gave no details of the probe.