Russia's S7 Airlines says a pilot was barred from a flight from Germany to Russia after traces of alcohol were found in his system.

Airline spokeswoman Irina Kolesnikova said the pilot had been set to make a flight from Frankfurt to the Russian city of Novosibirsk Saturday.

She said the pilot claims the test discovered residue from medicine he had taken, but that he will be fired if it is confirmed he had been drinking.

Frankfurt police said the test found a blood alcohol level of about 0.05 percent — the limit for driving a car in Germany and nearly twice the limit in Russia. Russian state TV said there were 150 passengers aboard the Airbus A320, which eventually made the flight with another pilot.

S7, also known as Sibir, is one of Russia's largest airlines.