Brazilian swimmer Glauber Silva was suspended for two years Wednesday and has lost his spot for the London Olympics after testing positive for increased levels of testosterone.

The Brazilian swimming confederation said Silva, who qualified to compete in the 100-meter butterfly at London, tested positive during a qualifying competition in May at Rio de Janeiro, where he earned his Olympic spot.

The confederation said two other Brazilian swimmers also were suspended for doping on Wednesday, becoming the latest in a series of cases involving local swimmers in recent years.

Flavia Delaroli was suspended for three months for testing positive for the substance tuaminoheptane, while Pamela Alencar was suspended for six months for testing positive for the diuretic furosemide.

Earlier this year, Barbara Benke tested positive for isometheptene and was suspended for four months. In 2011, four Brazilian swimmers tested positive for furosemide, including Olympic and world champion Cesar Cielo, who was later cleared to compete.

Also last year, swimmer Fabiola Molina was suspended for six months for testing positive for the substance methylhexaneamine, but went on to earn a berth at the London Games.

The confederation said Wednesday's suspensions came after the cases were analyzed by a doping panel that included four doctors and a representative of the international swimming federation.

Silva's personal doctor said in the swimmer's defense that the increased levels of testosterone were prompted by a hormonal imbalance in the athlete's body, but the panel said that tests showed "results consistent with the use of steroids."

Silva was temporarily suspended on June 16, so the two years began retroactively to that date. All of his results during the competition in which he tested positive were annulled.

The panel said that Delaroli's doping stemmed from a medication she had been using for years and had properly advised officials about it. The doctors said there was no intention from the swimmer to improve her performance, but that she was negligent for not properly taking the medication which is prohibited during competitions.

The panel also said that Alencar didn't intend to improve her performance, but suspended her because it was not "possible to precisely determine how the substance entered her body."

The athletes could not be immediately contacted for comment.