MOSCOW - No one will face criminal charges over the worst doping scandal in Russia's history, the country's sports minister said Friday.

A report in November by a World Anti-Doping Agency commission alleged systematic, state-sponsored drug use in Russian track and field and a widespread cover-up of doping.

The former head of the Russian track federation was also accused of a role in extorting 450,000 euros ($500,000) from a marathon runner and was later banned for life.

''The General Prosecutor's office carefully examined the report in question and did not find a single legally supported fact to open any kind of case,'' Russian Sports Minister Vitaly Mutko told sports portal Sportfakt.

Mutko's comments came a day after almost the entire Russian national under-18 hockey team was cut from next week's world championships and replaced with an apparently weaker under-17 squad. The change was announced the day before the under-18 team had been expected to fly to the United States.

Mutko said some players had taken meldonium while it was still legal but that Russian officials feared it could have remained in their bodies.

''If an athlete or a group of athletes took it in October or November, we don't know if it'll be found or not (in testing),'' Mutko said in comments reported by the state news agency Tass. ''We're minimizing risks.''

Russian Hockey Federation president Vladislav Tretiak had said the roster change was ''tactical,'' but the federation admitted Friday the switch was actually due to meldonium.

The federation claimed that players stopped using the substance in the fall of 2015 when WADA ruled it would be banned for 2016. Removing the under-18 team from the world championship was an attempt to ''defend the rights of young athletes,'' it said.

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