Shane Warne's hopes to stage a comeback into the World Cup team may remain a dream as there was little chance of his 'B' sample being free of the banned substance.

According to the Australian Sports Drug Agency, there was "scant chance of Warne's second urine sample being free of drugs."

ASDA chairman Dr Brian Sando said it was rare for a 'B' sample result to differ from the initial sample, known as the 'A' sample.

"Unfortunately for the athlete, it is very unlikely that specimen, which really is part of the original one, is going to show anything different from what the A sample has shown," Dr Sando said on Australian Broadcasting Corporation radio Wednesday.

The world's leading leg spinner is on his way back home after he pulled out of the Australian squad following news of a positive dope test for diuretic, a masking agent, in an ASDA sanctioned test last month.

The positive test was from Warne's initial urine sample. The 'B' sample, is now being examined.

Disappointed at Warne's positive test, Dr Sando said "the education programmes are pretty widespread."

"And I know cricket administrators have certainly participated in those programmes and have done their very best to educate their players about the dangers of taking prohibited substances and not getting caught by inadvertent use.

"But every year, unfortunately, we have a few of these top athletes who test positive to substances on that banned list, and it's pretty disappointing."

The ADSA chairman also said it did not matter if Warne had taken the banned diuretic inadvertently.

"Unfortunately from an athlete's viewpoint, there is strict liability. An athlete is responsible for what goes into his body. And so if a banned substance is found in urine testing then that athlete has to answer as to why and how that occurred," he said.

"But they really do have to pay a penalty because unfortunately it's not possible to differentiate frequently between those who have done something inadvertently and those who may not have been trying to do it inadvertently."