A cricketing superstar, a pill from his mother and a colourful career hit for six

Shane Warne flew home from cricket's World Cup last night with his career in grave jeopardy after announcing he had failed a drug test. But that was about the only certainty surrounding the great Australian bowler's astonishing withdrawal from the tournament: as usual with doping scandals there were many more questions than answers.

When he embarked on the journey from Johannesburg to Melbourne, Warne, the man who reinvented the art of leg spinning and became one of the five "Cricketers of the Century", could reflect that his wonderful and bizarre career might now be over. If a second test for a proscribed diuretic also proves positive he faces a ban of up to two years, by the end of which he will be 35.

Warne might also have spared a thought for his mother, Brigitte. She is reported to have given him the fluid reducing tablet on the day he was randomly tested last month, which was also the day before his comeback to the Australian team after dislocating a shoulder. There had been wide-spread amazement at the speed of his recovery.

He is expressilng a wish to return to the World Cup squad – the tournament lasts for six weeks after all – but the second test would have to be negative for him to have any hope of that. And he would still have some explanations to make. Ricky Ponting, Australia's captain in the World Cup, said last night after his team beat Pakistan in their first match: "He's been guilty of naivety for sure, or stupidity, one of the two. There is a fear it will end his career but I don't know and I don't think anybody will know until all the hearings have been held."

Organisers were left to rue the potential damage to the competition by the withdrawal of one of the sport's biggest (and few) drawing cards. Privately, at least, they felt it might give the World Cup publicity it would never have received otherwise.

But Dr Ali Bacher, the head of the South African organising committee, said: "All players were made well aware of the increased drugs testing procedure there would be at this World Cup and a doctor was sent specifically to the Champions' Trophy in Colombo last September to remind them of their responsibilities."

That was a point made repeatedly throughout the day: Warne, like all other cricketers, had been given plenty of warnings. As recently as 3 November last year the Australian Cricket Board (ACB) and the Australian Sports Drug Agency (ASDA) gave briefings to the players. ASDA organised the fateful tests on 22 January. They recorded evidence of the diuretics, hydrochlorothiazide an amiloride – both banned. The ACB and the International Cricket Council follow the guidelines set by the International Olympic Committee that make clear diuretics are prohibited because they can mask the presence of other banned substances in the body. Those other banned substances might be performance enhancing.

Warne looked drawn but sounded pragmatic when he spoke to reporters yesterday morning. His listeners knew what was coming but could still barely take it in. Warne spoke in measured tones as he declared he had decided to leave the squad – which was a case of acting before he was acted upon. Perhaps he recognised it as simply another twist in a life he frequently compares to soap opera.

This might be the biggest of all the controversies in which he has been embroiled but he has managed to emerge from all the others with dignity and reputation intact. His candour helps, and he tried to be candid.

"I was shocked and absolutely devastated," he said. "I am shocked because I do not take performance-enhancing drugs and do not condone them in any shape or form. I am proud to be in the shape I am at the moment and that is due to nothing other than hard work and looking after myself with diet.

"I did take a fluid tablet before my comeback game in Sydney, which I did not know contained a prohibited substance. The tablet actually dehydrates you and gets rid of any excess fluid in your body and, as I understand, is not performance enhancing."

Warne had spent most of his career as a tubby, peroxide blond genius. But, a year ago, he embarked on a regime of fitness and eating food more appropriate to a professional sportsman. "I still like chips but I don't have them every day," he said.

The result, in pretty quick time, was a reshaped leg spinner. He shed two stones (13kg) in well under a year and, when he arrived in England for a book promotional tour last summer, it was observed his cheekbones could be seen for the first time.

Warne's intention was to extend his career, and for that he knew he had to be fitter. Last month, he went a step further and announced his retirement from one-day international cricket. The World Cup was to have been his swan song.

His mind was concentrated when he dislocated his shoulder against England in the first pat of the one-day series in December. Indeed, there were fears at the time that his place in the World Cup was at serious risk. Yet, barely more than a month later, he was back. The pe'iod of his rehabilitation caused considerable surprise. Some pundits said it could not be done. Warne put it down to hard work and the attentions of the Australian physiotherapist, Errol Alcott.

The ACB has a well-established programme of testing for drugs and had banned two players before. One, Graeme Rummans, was eventually let off a with a suspension of month, having administered a banned drug to treat a boil. The other, Duncan Spencer, a bowler, who once played for Kent, served 18 months for taking an anabolic steroid.

Warne will appear before a hearing after the result of the second test. That will be held in Melbourne "as soon as practicable" but Warne hopes it can be next week. His case will be heard by the ACB's anti- doping committee, whose regulations allow it to impose a ban of up to two years.

James Sutherland, the chief executive of the ACB, who appeared with Warne at the hearing, said it commended Warne for his open and co-operative approach.

But perhaps when he left Johannesburg yesterday, Warne was departing an Australian team for the last time.

THE 'FLUID PILL'

Diuretics are prescribed to patients with high blood pressure or heart or kidney disorders. They stimulate the kidneys to produce extra urine and reduce fluid in the tissues. Jockeys and boxers use them to lose weight rapidly through the elimination of fluid. They can also act as masking agents, to conceal substances such as steroids – taken to build up strength, particularly after injury – by excreting them quickly. They can lead to dehydration, causing dizziness, cramps, headaches and nausea.

NATURAL BORN SPINNER WARNE'S UP AND DOWNS

December 1991: Leaves the Australian Cricket Academy. Later admits that if he had not left voluntarily, expulsion loomed.

June 1992: Becomes first student of the academy to play for Australia. Takes 1-150 on his debut against India.

August 1992: Australia are heading for defeat against Sri Lanka in Colombo. Warne then takes the last three wickets for 11. Australia win.

June 1993: Takes a wicket with his first ball in an Ashes Test match with a phenomenal turning leg break that bowls Mike Gatting behind his legs.

September 1994: While playing in a one-day tournament in Sri Lanka he is approached for information on a match. He and team-mate Mark Waugh take A$11,000 (£4,000) for their advice.

July 1998: Has reconstructive surgery on his bowling shoulder.

June 1999: Part of Australian team that wins World Cup. Man of the match in both the semi-final and final.

March 2000: Accused of grabbing a camera from a teenager who pictured him smoking. Warne is being paid A$200,000 by a nicotine substitute firm to give up cigarettes. The father of the boy drops the complaint and Warne collects his fee.

April 2000: Named one of the five top cricketers of the 20th century by Wisden.

July 2000: Leaves lewd voice messages on the mobile phone of a nurse he met in a nightclub. She sells the story. Warne is stripped of the Australian vice-captaincy.

December 2002: Dislocates shoulder in one-day match against England. Returns to action far quicker than expected to play in finals of one-day series.

January 2003: Announces World Cup will be his last one-day internationals.