Pakistan bowler Mohammad Asif protested his innocence on Monday after it was confirmed he had failed a dope test during the Indian Premier League earlier this year.
"I have taken no banned substances or drugs and I am innocent," Asif told Reuters in a telephone interview.
"I am hoping the board will support me and help me clear my name. I will take a decision on having the sample 'B" tested after consulting with the board," Asif said.
"I just don't know how this has happened because I have been very careful with the medicines I use," he said.
The 25-year-old was left out of Pakistan's Champions Trophy preliminary squad once the positive was confirmed by the organisers of the Indian Premier League on Monday.
"Obviously in these circumstances he can't be considered for selection. The board has officially informed him of his positive test," Zakir Khan, the PCB's director of cricket operations, said on Monday.
Khan said Asif had the right to appeal and ask for a B sample test, but the board would be discussing the issue with him soon.
"We have been told his test was conducted on May 30 and which has come as positive. We are disappointed and shocked at this development," he said.
Asif, who has played 11 Tests and 31 one-day internationals, was last month detained in Dubai for 19 days for alleged possession of a banned substance.
He was released by the authorities without being charged but a Pakistan board committee is probing the incident to see if he violated its anti-doping regulations.
After his detention, Asif claimed the substance found on him was a ayurvedic medicine he was prescribed by a local Hakeem (ayurvedic practitioner) for his elbow injury
A board official said it would investigate the issue of Asif using ayurvedic medicine and speak to the person who prescribed it to the player.
"We have to see now what substance exactly has been found in his tests," the official said on condition of anonymity.
