The comments signalled a deepening of a row in which Russia has cited turbine problems as its reason for cutting gas supply via Nord Stream 1 - its main gas link to Europe - to just 20% of capacity from Wednesday.

Vitaly Markelov, Gazprom's deputy chief executive, also said Russia had complained repeatedly to Siemens Energy about problems with other turbines.

"We have repeatedly applied to the Russian representative office of Siemens about this, sent 10 letters. Siemens fixed no more than a quarter of the identified bugs," he said in a TV interview.

He cited the serial numbers of three other engines that needed repair by Siemens because of faults in May and June that had put them in a state of forced downtime.

The European Union disputes Russia's and Gazprom's argument that turbine problems are to blame for the sharp drop in supply through the pipeline that links Russia to Germany under the Baltic Sea. The shortfall has raised the risk of shortages and gas rationing in Europe this winter.

Siemens Energy has previously countered Gazprom's criticism over its service by saying it is up to the Russian company to file customs documents for the turbine's return.

With both sides trading economic blows since Russia sent its troops into Ukraine on Feb. 24, the EU has accused Russia of energy blackmail, something the Kremlin denies.

Markelov said the turbine that had been serviced in Canada had still not arrived back in Russia.

"It was sent to Germany, not to Russia, without Gazprom's consent," he said, adding that this created sanctions risks.

Gazprom also needs to send for repair other turbines from the Portovaya compressor station. "There is no clarity that the maintenance of the gas turbine engines will not fall under the sanctions," Markelov said.

(Reporting by Reuters; Editing by Mark Trevelyan and David Holmes)