Italian prosecutors say Eni subsidiary Agip Kco is suspected of offering bribes to Timur Kulibayev, son-in-law of the Kazakh president, through 2007, Russia's state-run news agency RIA Novosti reports.
As a result, the Milan court said Eni might be banned from work in the Kashagan oil field in the former Soviet republic. Bribes through 2007 may have totaled at least $20 million, though the news service suggests they were meant for investment purposes.
The Russian news service said Eni Chief Executive Officer Paolo Scaroni might be charged with backing international corruption if the allegations are found to be correct.
Mario Reali, the former head of Eni offices in Russia, told investigators in June about alleged payoffs related to contracts in Kazakhstan. This led investigators in Milan to look into similar allegations related to the Jurassic oil field in Kuwait and the Zubair oil field in Iraq, for which Eni landed contracts in 2010.
Eni is also under investigation by the U.S. Securities and Exchange Commission for alleged corruption in Libya.
The Kashagan oil field is one of the largest in the world.