A "urine barrier" kept Forester kangaroos away from a garden full of rose beds for a month.

Film footage of the kangaroos showed them freezing about five metres from the garden's edge, before turning tail and hopping away.

The raw urine was collected from animals kept at the Australian Dingo Conservation Association in Canberra, and flown fresh to Perth.

But its limited supply - there are only a few dingoes in captivity, and pure-bred dingoes are a vanishing breed in the wild because of inter-breeding with feral dogs - means that the gel is expensive.

A 40ml bottle costs A$20 to produce - hence the necessity to come up with an artificial replica.

Researchers found that dingo urine contains a surprisingly complex range of chemicals. "We're talking about 200 different elements, from pheromones to minerals," Dr Parsons said today.

Each chemical will have to be carefully copied by scientists at the government-run Chemistry Centre in Western Australia.

"Twenty years ago this wouldn't have been possible. If we can synthesise it then we can reduce the cost of a bottle to a matter of cents rather than $20. We're looking at 2010 as our target date," said Dr Parsons.

"We're really excited because we've shown that dingo urine works as a deterrent. "It's a humane, safe, biodegradable alternative to trapping, shooting and poisoning."

The project, which was recently awarded a A$1.6 million grant, is supported by the Australian RSPCA.

The gel is likely to be of interest not only to timber companies but by gardeners fed up with the night-time marauding of their local possum population.