Russia is at risk of being suspended from international swimming competition following a series of positive doping tests, the country's sports minister says.
Last month, world record-holder Yuliya Efimova was banned for 16 months after testing positive for a banned steroid.
Two other Russians were serving suspensions after failing drug tests and at least five were banned last year, mostly for domestic violations.
The case came as Russia prepared to host next year's world swimming championships in Kazan.
''The number of breaches of anti-doping rules in the international arena is on the brink,'' Vitaly Mutko told Russian media overnight.
''One or two more breaches and the federation could be suspended altogether.''
Mutko said the Russian Swimming Federation was one of ''several'' Russian sports bodies at risk of suspension over doping scandals. He did not name any others.
According to the statutes of swimming's world governing body Fina, a member federation received a two-year ban if four of its competitors in the same discipline commited doping offences within 12 months, with certain exemptions.
Fina executive director Cornel Marculescu said that Russia was not currently in that category.
''I will not further comment on this possibility,'' he said.
Marculescu said that he and Fina remained ''fully confident'' in Russia's ability to host the world championships.
Two Russian swimmers were currently awaiting verdicts in their own doping cases in international competition.
Sergei Makov tested positive for the banned muscle-building substance ostarine at a World Cup event in Moscow in October.
Vitalii Melnikov tested positive for the blood-boosting hormone EPO at last year's European short course championships in December.
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