JAIPUR, Oct 19: Pakistan coach Bob Woolmer on Thursday offered a fresh theory as to why Shoaib Akhtar and Mohammad Asif failed drugs tests.

Both fast bowlers were found to have excessive amounts of nandrolone in their system, and were sent home from the Champions Trophy on Monday, denying Pakistan the services of two key pacemen.

Woolmer suggested that Shoaib and Asif may have bought over-the-counter products designed to help bulk them up, without realising the impact of their use.

"We know what we've given to the players," Woolmer told Sky Sports News. "Our doctors, our physiotherapists, are very strict. That's why it came as a shock to me.

"If anything is happening outside our sphere of influence, then I don't know about it. That's what will worry me, if something's happening outside our sphere of influence."They might have been taking a build-up powder which we didn't know about and which you can pick off the shelves which has nandrolone in it, and there are substances like that. I don't know whether they've picked them up off the shelves. I don't have any answers unfortunately."

Both Shoaib and Asif received injections during their rehabilitation from injuries this summer, Woolmer revealed yesterday, adding that they were not administered by any of his medical team or anyone within the PCB, to his knowledge.

Both bowlers face an anxious wait before they discover their fate. An independent tribunal is likely to be formulated by the Pakistan Cricket Board when they convene in Lahore on Friday.—Agencies