ATP Tour trainers will no longer dispense electrolyte tablets or other vitamins and minerals to players, after an investigation showed products they distributed could have been contaminated by a steroid and caused the suspension of a Czech player.

Tour officials made the immediate policy change Wednesday and also announced the reversal of Bohdan Ulihrach's two-year drug suspension for using the banned steroid nandrolone.

The ATP became aware of the possibility that it was mistakenly giving out contaminated products in May, when an unidentified player tested positive for nandrolone and said he was only using ATP-provided electrolyte tablets that help avoid dehydration.

Until that allegation, tour officials were unaware that their trainers were making electrolytes available to players.

"The ATP trainers were dispensing products the ATP itself was advising players not to take,'' said Mark Young, ATP executive vice president and general counsel.

Ulihrach took the ATP-dispensed tablets at a tour event in Moscow last October, then tested positive for nandrolone. He was suspended in May by the ATP Tour and the International Tennis Federation for two years, fined $43,770 and lost 100 ranking points.

An independent Tennis Anti-Doping Program tribunal determined Tuesday that the ATP should not "enforce its anti-doping rules if it appeared ATP trainers were the sources of the ingested substance.''

All penalties against Ulihrach were dismissed, and he is immediately eligible to play professional tournaments.

"I am extremely pleased that this episode in my life is now behind me so I can return to doing what I love to do most: play tennis,'' said Ulihrach, a winner of three singles titles and more than $3 million in prize money during his career.

The tour will not compensate Ulihrach for lost earnings and does not expect the player to contest the matter further, Young said.

ATP officials isolated 43 cases, all chemically similar and determined to be consistent with the unintentional ingestion of a supplement containing trace amounts of nandrolone. Low levels of the steroid were found in all of those tests.

Further analysis found that all players involved in those 43 tests appeared to have taken the same electrolyte, which contained such low levels of the steroid that they could not have enjoyed any performance enhancement as a result, said Christiane Ayotte, the director of the International Olympic Committee's Doping Control Laboratory in Montreal.

Those tests did not result in any other suspensions.

"We were unable in the investigation to prove that the electrolyte tablet was contaminated, but it was the only common denominator in the cases,'' Young said.