The Pakistan cricket Board on Monday said it would continue carrying out random and unannounced dope tests of its players before the Champions Trophy to keep the sport clean of drug cheats in the country.

"We did the dope tests of the players picked in the preliminary squad of the Champions Trophy and their reports are expected in next three to four days. But our process of keeping the sport clean will continue," Zakir Khan, PCB Director (Cricket Operations) said in Lahore.

"We will continue to have random dope tests before the tournament which is an International Cricket Council (ICC) event and they will also have their own random tests," he said.

Pakistan cricket has been hit hard by doping scandals in recent times with fast bowlers, Shoaib Akhtar and Mohammad Asif testing positive for a banned substance in 2006 ahead of the last Champions Trophy in India.

They escaped bans winning an appeal with an appellate tribunal but in June Asif spent 19 days in detention in Dubai over alleged possession of a banned substance.

This month Asif was again in the news when he tested positive during the Indian Premier League.

There have also been rumours of some players using hashish and marijuana in domestic cricket in dressing rooms and otherwise.

Zakir said the Board was keen on ensuring that all players were clean and they would be enforcing a system of dope testing at the domestic level soon.

"We are working on its details and mechanism as these tests are costly," he said.