Rome prosecutors say Angelo Caridi, the former head of refining marketing, and manager Angelo Fanelli, falsified invoices related to excise duty on orders of liquified petroleum gas (LPG), according to a report in Corriere.

A businessman named Roberto Turriziani was also allegedly involved in the fraud, which reportedly allowed the men to “deceive tax authorities for years” and was instrumental in creating a secret "slush fund".

Investigators on Tuesday searched the headquarters of Eni Servizi, a subsidiary in the Lombardy town of San Donato Milanese, as well as seven homes owned by Caridi in Rome, Reggio Calabria, San Donato and Anzio.

Caridi, 67, is said to have played a “pivotal” role in the tax fraud, which prosecutors estimate exceeded €2 million.

“But we estimate the damage to the State is much higher; this is a focus of the ongoing investigations but also to identify how the money was re-used.”

In a statement to The Local, Eni said it is paying "great attention" to the investigation, which got underway two years ago, and assured "full cooperation" with the authorities.

The company added that the case related to “a relatively small industrial activity carried out by the former head of the refinery and marketing division.”

Although Caridi is now retired he is still remains on the staff books of subsidiary Eni Servizi, earning him a “fee” of €193 million a year.

A spokesperson for Eni was unavailable for comment when contacted by The Local.