Nine days ago, Farrell, 38, was immediately stripped of his competition licence after returning a positive result in a random test at a World Series Sprintcar meeting in Bunbury. The test was conducted under the supervision of Speedway Australia, the peak speedway body affiliated with CAMS and the FIA. He faces a ban of up to two years.

Farrell admitted to the positive result and apologised to fans, sponsors and the sport. He said he had been dealing with depression and drug use for a long time and was getting counselling. It was the second known lapse for seven-time WA sprintcar champion Farrell. In 2010, he was convicted of a methamphetamines possession charge in the Northern Territory.

There's a feeling on the eastern side of the Nullarbor that drug use in speedway may be more prevalent in the wild west than elsewhere. Commenting on the Farrell case, operations manager Paul Trengove said Speedway Australia had a zero-tolerance policy for prohibited substances and was determined to maintain the sport's integrity and safety. He said about 50 tests were carried out annually and that WA competitors were subjected to their share.

The Farrell bust is a rare black mark for the broader speed sport. It's fair to say substance abuse has never been a major issue in international motor sport, although drug running has. Drivers and riders are rightly concerned about racing wheel-to-wheel with a rival whose physical and mental state might be affected by illegal stuff.

CAMS told Fairfax Media it had conducted anti-doping tests (including those for illicit drugs) on about 350 competitors since 2000. Only seven were positive, including one older driver whose anti-baldness "cure" was on the ASADA banned list. “All sports are on high alert after the ACC report,” said a CAMS spokesman. “We are looking at what we have in place and whether we need to do more.”

There may be lusty gossip occasionally linking riders and drivers to Lycra-clad grid girls, but it's hard to recall specific innuendo connecting competitors and drugs. John Bowe, who has a slight nicotine habit, is an anachronism in a sport of diet and fitness-fixated people.

Still, there have been occasional busts, but very few locally. A few years ago the prodigiously talented Anthony Gobert slowly turned into a walking rap sheet and saw a potentially stupendous world championship riding career disappear in a smoke cloud. Another two-wheeler hero, high-flying former Australian champion motocrosser Kim Ashkenazi was jailed for 6� years in Britain for possession of cocaine with intent to supply.

Last July, NASCAR driver A J Allmendinger was suspended indefinitely after traces of amphetamine was found in a urine sample. He later revealed the drug was Adderall, often used by students when cramming. Two months later, he was reinstated after completing NASCAR's Road to recovery program.

Driver Shane Hmiel failed three drug tests and was banned for life. The ban was later lifted and he was paralysed in a racecar crash in 2010.

Jeremy Mayfield, winner of five NASCAR races, hasn't raced since 2009, when he was suspended indefinitely for testing positive to methamphetamine. Two years ago Mayfield was arrested for possession of methamphetamine.

The thorny issue of drugs in motor sport has certainly toned down since the 1980s, when for a time American sports car racing seemed to operate on the proceeds of moving illegal party propellants across borders. Race grids were laced with expensive prototype cars suspiciously bereft of any sponsorship.

The Whittington brothers Don and Bill, 24 Hours of Le Mans winners with Klaus Ludwig in 1979, lost their Miami suntans for long periods after being convicted of money laundering (Don) and income tax evasion and conspiracy to smuggle narcotics (Bill). At one point they were rich enough to own the Road Atlanta racetrack.

More notorious was Randy Lanier, a sometimes sports car racer and Indy driver and partner of the Whittingtons. He copped life in jail in 1987 for importing and distributing 300 tonnes of Colombian dope.

Versatile racer American John Paul Sr was something of an all rounder in crime too, his misdeeds running to importing marijuana, tax evasion, possession of a false passport and the attempted murder of a federal witness. He spent 13 years in prison but remains a wanted man after a mysterious disappearance of a girlfriend. Later his talented car racing son John jnr became implicated in his father's drug trafficking. He also did time, resumed racing but retired with medical issues.

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