Investigators said Wednesday the pilots of a Russian plane that crashed, killing the entire Lokomotiv Yaroslavl ice hockey team, had been inadequately trained and the co-pilot was under banned sedatives.

They also faulted poor inspections of the Yak-42 jet, which ploughed into a riverbank just after takeoff as it set out to carry the team to a match in Belarus. All but one of the 45 passengers died.

The September 7 crash, less than six months after another airline disaster killed 45 people, raised fresh concerns about Russian aviation safety and prompted President Dmitry Medvedev to call for a cut in the number of small regional Russian carriers.

Russia's aviation safety watchdog, Rosaviatsia, last month revoked licenses held by the airliner's operator, Yak Service.

The airliner nosedived into the River Volga after takeoff from a provincial airport some 250 km (250 miles) north of Moscow, said Alexei Morozov, who headed a commission investigating the crash.

Despite the engine being in flight mode the plane's speed did not increase, he added.

He said the flight training undergone by the two pilots was insufficient to acquire the level of skills necessary to pilot and manoeuver this type of Yak-24 aircraft.

An autopsy revealed the co-pilot was under the influence of a type of sedatives banned on the job but which is widely prescribed to treat anxiety and seizures, he said.

Phenobarbital, a prescription which has a slowing effect on the central nervous system and is banned for pilots, was found in the body of the co-pilot, Morozov said.

The only player from the 37-member ice hockey squad to survive the air crash in western Russia died of burns last month, leaving a flight engineer as the sole survivor.

(Reporting By Alissa de Carbonnel; editing by Andrew Roche)