Ambassador Mahmoud Reza Sajjadi made the complaint public through the media in Moscow.
It is the first official confirmation that the oil division of Gazprom had taken over from the Statoil-Lukoil partnership at Azar in late 2009, despite the threat of US sanctions.
Gazprom Neft has never responded to media reports of an agreement over Azar and it makes no mention of the project on its list of business prospects outside Russia.
