JUN 5 - An Australian oyster farmer has hit upon a technique he believes has created the ultimate aphrodisiac -- feeding his shellfish the drug Viagra.

George May said the natural qualities of the oyster, known for arousing sexual desire, combined with the best modern pharmaceutical equivalent to create a potentially multi-million dollar market.

"First of all, oysters are the greatest natural aphrodisiac, second, you lace it with Viagra, and third, it's a laugh," the 59-year-old told AFP on Monday.

May, who was a successful Sydney marketing executive until being diagnosed with prostate cancer late in 2006, will not be allowed to sell his oysters in Australia because they contravene strict regulations.

And he has been ordered by pharmaceutical giant Pfizer, which produces the anti-impotence drug Viagra, to stop using the name of their most famous product in his marketing.

But May says neither of these obstacles will stop him from exporting his specially prepared Sydney Rock Oysters around the world.

"No-one can stop me feeding Viagra to my oysters. The reason that Pfizer are jumping up and down is that I used the name Viagra," he said.

"I'm getting calls from Macau, Hong Kong, Moscow for god's sake. I'm getting calls from all over the bloody world."

May, a self-described "marketing genius" from Scotland, said the idea came to him after he started "hanging around with the boys" in the small fishing village north of Sydney he retired to following prostate surgery last December.

His doctor had prescribed a small daily dose of Viagra to help his recovery and it occurred to him he should be feeding the drug to oysters to help the local farmers, many of whom had struggled after a disease swept through their crops.

May said he told them: "I'm going to feed them Viagra and zinc and every other aphrodisiac I can find."

He has since patented the idea of feeding the oysters Viagra, magnesium, zinc and sea grass among other things after the shellfish have gone through the normal purification process.

"They are all being really well looked after because they are in beautiful filtered water and we're actually feeding them vitamins and minerals," May said. "We're getting a bigger oyster."

May now has some 10 million oysters in cultivation and says he eats one to two dozen each day without any ill effects of consuming a foodstuff containing some medication. "I swear to god. They work," he said.

A spokesman for Pfizer said the drug company was concerned about the use of their brand name. "It's a very ordinary trademark issue," he said.