Finance police seized documents at the offices of Italian energy group ENI on Monday in connection with a Milan-based probe into suspected fraud in gas measurements.
ENI Managing Director Paolo Scaroni was among the energy sector executives under investigation as part of a probe which also involves Milanese energy utility AEM and northern gas supplier Arcalgas.
Police carried out searches in offices used by the three companies in Rome, Milan, Turin and Piacenza.
Details of the suspected fraud were not immediately available but prosecutors were reportedly considering possible breaches of tax laws and obstruction of inspectors.
"We are not worried," said Scaroni, adding that he had verified the validity of measuring systems with the help of international consultants.
The measuring instruments at the centre of the investigation have no impact on the gas bills received by millions of Italian households, the group said in a statement.
Shares of ENI and its gas distribution unit SNAM Rete Gas both fell on the Milan bourse as news of the tax police investigation emerged. ENI was down 1.2% and SNAM 0.62% at midday. AEM shares also fell 1.5%.
