Eni is under investigation for allegedly "suspicious payments" of around $268 million related to contracts for its oil subsidiary Saipem in Algeria.
The company issued a statement saying a result of an external audit found the allegations were without merit.
"The results of the audits revealed neither evidence of illegal or corrupt conducts of Eni, nor the existence of intermediary contracts between Eni and the third parties under investigation," it said Thursday.
Last month, the Italian energy company said it signed an agreement with corruption watchdog Transparency International, which it said "confirms the importance given by Eni to business ethics."
Eni didn't identify the party conducting the audit but said it would immediately release results of the finding to the relevant authorities.