Pacemen Shoaib Akhtar and Mohammad Asif, who returned positive dope tests last year, were among a batch of Pakistani cricketers to clear their latest screens, an official said on Saturday.
"Akhtar and Asif are among 26 players who have cleared these tests for which we asked urgent reports from the World Anti-Doping Agency (WADA) accredited laboratory in Malaysia," PCB director of communications Ahsan Malik told AFP.
The tests were conducted Monday and Tuesday.
Akhtar and Asif were the focus of attention when the Pakistan Cricket Board (PCB) decided to conduct these tests ahead of the Twenty20 World Cup to be held in September in South Africa.
The new-ball partners tested positive for the banned steroid nandrolone in tests conducted internally in Pakistan before the ICC Champions Trophy last year. They were withdrawn from the Pakistan team for the tournament.
A PCB doping tribunal banned Akhtar for two years and Asif for one year, but the bans were controversially overturned by an internal tribunal on appeal.
Pakistan also conducted pre-World Cup tests in February in which Akhtar and Asif did not appear. The duo was then pulled out of the World Cup due to injuries on the day the team left for the West Indies.
Pakistan suffered a humiliating exit from the World Cup after a three-wicket loss to first-timers Ireland.
Malik said the PCB expected all tests to be negative in accordance with its zero tolerance policy on doping.
Three of the players -- Younis Khan, Danish Kaneria and Yasir Arafat -- are currently in England playing county cricket and have been tested abroad, Malik said.
Pakistan is due to announce its squad for the Twenty20 World Cup next week.
Pakistan probables are attending a tune-up camp which concludes at Karachi on Monday. The team's new coach, Australian Geoff Lawson, is due to join them on August 20.
Lawson replaces Bob Woolmer who died during the World Cup in March.
Pakistan will open the Twenty20 World Cup against Scotland on September 12 before meeting arch rivals India two days later.