Russia’s aircraft maintenance capabilities are crippled by Western sanctions.
According to the flight tracking system, Flightradar24, the Airbus A330-300 flew to Tehran on April 5 and remains there until now.
"The maintenance of the Airbus A330 aircraft (in Iran) will be implemented by a provider for a wide range of work," Aeroflot said in a statement, Reuters reported.
RBC media outlet first reported about the maintenance in Iran.
"The firm has all the necessary material resources, certificates and extensive experience, (while) the provider performs maintenance with a high quality level," the Airline said.
Aeroflot declined to comment on details and did not name the operator that will carry out the repair.
Sanctions imposed on Russia after it sent its troops into Ukraine in February last year have prevented its airlines from obtaining aircraft and spare parts or undergoing maintenance in the West.
Russian airlines continue to operate Western jets, but struggle to import replacement parts.