Mr Vaisman claims almost 500,000 men over the past decade have responded to AMI's billboard-sized promises of longer lasting sex. The NSW regulator believes the disaffection is probably much higher than the actual complaints received as men are too embarrassed to lodge formal complaints over the $4000 contracts which commit them to 18 months of "treatment" and severely limit their access to the company's money-back guarantees.

The thriving business predicated on men's sexual-performance anxiety has delivered millions of dollars to AMI coffers and spawned more than 20 clinics in Australia and New Zealand, and, most recently, a discreet consultancy in London. Last year AMI, registered as a public company on the US NASDAQ, posted an almost 50 per cent increase in gross profit, from $8million to $12million, in the July to September quarter alone - profit the company attributed to its more effective advertising campaigns (at a cost of $500,000 a quarter), increased brand name recognition, and the effectiveness of its products. Yet AMI's founder and owner Mr Vaisman, a portly Ukrainian migrant in his early 60s with a good suit and a comb-over, denies he is a very wealthy man. Comfortably off, he'll concede. But far from accumulating personal wealth, Mr Vaisman claims he is delivering savings worth millions of dollars to Australian taxpayers every year.

"All my consultations, we never use Medicare," he said. "Can you imagine if 90,000 impotent patients went to their GP every year? At $45 or $50 a consultation, what would happen? The Government would lose millions of dollars." Sexual dysfunction, says Mr Vaisman, is a quality of life condition and if you want quality of life you have to pay: "It's like if you want a better car or you want a better house, you pay more money."

Mr Vaisman is under fire from multiple corners, but that is hardly new. In 1996 his former company, On Clinic Australia, was prosecuted for importing $500,000 worth of unregistered drugs - the charges were proved but no conviction was recorded, with the Court of Criminal Appeal acknowledging the probably inadvertent nature of the offences. Aside from much-publicised run-ins with the Advertising Standards Bureau, there has also been attention from the Australian Competition and Consumer Commission over allegedly misleading claims relating to his controversial treatments and AMI's promises of guaranteed results or money back. Mr Vaisman rejects the latter allegation outright: "We cannot guarantee a result but we always guarantee money back." Meanwhile, the chorus of caveats and criticisms from the medical fraternity multiplies monthly.

Dr Chris McMahon, associate professor of the Australian Centre for Sexual Health, has dealt with former AMI patients, and alleges the majority have not received what they thought they paid for. AMI's apomorphine-based nasal spray has not been the subject of clinical trials, so its efficacy remains untested, he says.

"There's a certain logic to it," he conceded. "I could also argue that because Panadol is effective as a tablet for a headache we could crush it up and put it into some K-Y Jelly and rub it into the scalp. Now we all know that is ridiculous - the way that you would prove or disprove that is to do a clinical trial." The non-profit Impotence Australia receives on average about five complaints about AMI each week. When patients fail to respond to the nasal spray, lozenges are offered but invariably the patient ends up facing injection therapy, the association's chief executive, Brett McCann, says, which is where many men will draw the line. "[I've seen] one guy who had only one arm … It is pretty difficult to inject when you've only got one arm. He said he would never have agreed to it had he known."

But formal complaints are comparatively rare, says Professor Basil Donovan, from the University of NSW's National Centre in HIV, Epidemiology and Clinical Research. "Men are too embarrassed to come forward," he said. "It is an area prone to exploitation."

The Australian Medical Association has expressed concern that some of AMI's initial customer contact does not involve a registered medical practitioner. Moreover, the company's practice of conducting phone consultations is unlikely to identify health issues such as heart disease, stroke, obesity and diabetes that can often be underlying causes of erectile dysfunction, AMA president Dr Rosanna Capolingua says. Dr David Malouf, the vice-president of the Urological Society of Australia and New Zealand, says the treatments AMI offered at large mark-ups could be provided at a much cheaper rate by a GP. "But the reason [GPs] don't is because these treatments are less effective than others, such as Viagra, Cialis and Levitra."

Such mainstream treatments are also largely without the horror side effects sometimes associated with injectibles, says Dr Malouf, warning that 30 per cent of men may develop local pain at the site of the injection. "I've seen bruising, scarring, curvature of the penis and priapism [persistent painful erection]. I had one patient who was treated with one of these agents. He was given a sheet of paper with a number to call if anything went wrong, which it did. He was effectively told [by AMI] 'there is nothing we can do, you have to go to a hospital emergency department' … That case of priapism was so severe, it permanently damaged his erectile function. He went from having a mild erectile problem to having a non-functioning penis. And he was a young guy, too."

Dr Malouf says he also had a 17-year-old boy who was prescribed treatment for premature ejaculation from an AMI clinic: "I would have thought that was entirely inappropriate." When The Sun-Herald put this to Mr Vaisman last week, he said: "If a patient asks for help, does it make any difference of the age?" The following day, public relations firm Wilkinson Media issued a statement saying AMI had a policy of not providing treatment to people under the age of 18.

Mr Vaisman has never been registered as a medical practitioner in Australia, a sacrifice made, he claims, to stay in this country. With a mother, wife and daughter to support - the former two suffering serious health problems - a year-long hospital internship was out of the question when the Ukrainian-trained doctor arrived in 1987: "This was the price I had to pay for my freedom." That much of the clinics' work with clients takes place over the phone is logical, Mr Vaisman argues, as erectile dysfunction is very much a self-diagnosed condition.

"If a patient says to the doctor, I cannot get an erection, there is no test that can prove or disprove this, you have to take his word." It is also an effective technique, he says, in protecting anonymity. With the exception of occasional crustiness or bleeding around the nose, Vaisman says his nasal sprays have practically no side effects. The risk of priapism is no more prevalent with the use of injectibles than with more conventional treatments such as Viagra, he adds, while AMI's 24-hour hotline is available to advise in such emergencies.

Mr Vaisman says Impotence Australia, one of AMI's most vocal critics, is in direct competition and accepts sponsorship from large pharmaceutical companies such as Viagra's manufacturer, Pfizer. Impotence Australia declares it accepts sponsorship from pharmaceutical companies on its website, but denies the direct competitor claims made by Mr Vaisman.

"We're not offering any treatment," said Mr McCann. "We refer people either to GPs or sex therapists or we give general information." Mr Vaisman describes himself as a pioneer: "We have a lot of criticism. But I am fighting for what I believe is right. I am a fighter."