The International Rowing Federation (FISA) handed out two-year bans to three Russian rowers for using prohibited intravenous injections during last year's world rowing championships.
Alexander Litvintchev, Evgeny Luzyanin and Ivan Podshivalov each will be out for two years, even though none of the substances they injected were illegal.
All three suspensions are retroactive to last Aug. 27.
Three other Russian rowers — Vladimir Varfolomeev, Denis Moiseev and Svetlana Fedorova — were also banned for using the same doping method in August.
Officials investigated the six athletes by using DNA analysis of blood after traces of intravenous infusion equipment were found in a garbage bin outside the Russian team's hotel in July.
"We hope that this is a clear message that the sport of rowing will not accept use of substances or methods that create unfair conditions and/or threaten the health of our rowers," FISA chief Matt Smith said.
Despite finishing seventh at the 2007 world championships, the Russian men's eight qualified for the Olympics this year in Beijing. But FISA wiped out the result and disqualified the boat.
Russia can still advance to the Olympics at the final qualifying regatta in June.