A reliable source in the Pakistan Cricket Board told PTI that the test of Hasan’s first urine sample, taken during the Pentangular Cup in Karachi in January, tested positive for cocaine.
"The results of the second sample are still awaited but on basis of the first sample results, the board has already established a two-member committee to charge-sheet the spinner and seek an explanation from him," the source added.
Hasan, 22, who played one One-Day International and 10 Twenty20 Internationals, has been advised to hire a lawyer to reply to the committee that includes a qualified sports medicine doctor and former Test player, Colonel Naushad Ali.
"The PCB is taking the matter very seriously because this is the first time any player has tested positive for the use of cocaine," the source said.
"If Hassan can't clear himself before the inquiry committee, he faces a two-year ban from all cricket," he added.
Pakistan fast bowlers Shoaib Akhtar and Muhammad Asif had tested positive for banned substances and had to be dropped for the 2007 World Cup because of the problem.
Image: Pakistan's Raza Hasan appeals successfully for the wicket of Shane Watson during the ICC World Twenty20 2012 Super Eights Group 2 match against Australia at the R Premadasa Stadium in Colombo on October 2.
Photograph: Pal Pillai/Getty Images