Cricket's world governing body said on Wednesday that players at the upcoming World Cup would be "target-tested" for drugs.
In addition to the already announced four random tests at each match, the International Cricket Council (ICC) announced that 17 of the scheduled 51 games in the Caribbean would be selected for additional testing.
The ICC, which is holding a series of board meetings in Cape Town, said its decision to target players was in response to positive tests for two Pakistan bowlers, Shoaib Akhtar and Mohammad Asif.
The pair tested positive for the banned steroid nandrolone but had their cases thrown out on appeal by the Pakistan Cricket Board.
"Both Shoaib Akhtar and Mohammad Asif have played for Pakistan over the past few months despite testing positive for prohibited substances last year," ICC chief executive Malcolm Speed said on Wednesday.
"That is a fact neither player has disputed and it is also a fact that has caused the game a high level of embarrassment as a result. We want to make absolutely sure that all players who take part in the ICC Cricket World Cup do so on the basis that they are free from banned substances," he said.
"From an ICC perspective, having the option to target test as well as the already-scheduled tests in place means that if a player does have anything in his system then there is a very strong possibility he will be caught out," he said.