Scientist Barry Hayes says the highly effective bacteria used to generate Ingard and Bollgard cotton – Bacillus thuringiensis (Bt) – could be the basis for a natural defense against the sheep blowfly.

Mr Hayes, of Geomite, says Bt has been found to effectively kill sheep blowfly larvae when combined with a protein bait for the flies to lay eggs in.

However, despite offering them the patent, he says Australian Wool Innovation (AWI) has not trialed it.

"Here I have an idea with real scientific merit and it's not interested," he said.

When ingested by fly larvae, Bt release a deadly toxin that kills maggots within 12 hours.

By drenching sheep with a mix of the bacteria spores and gelatin protein, both pass through the sheep's digestive tract and are expelled in the dung.

As the maggots require protein to grow (hence their flesh eating nature), the flies are drawn to the dung.

However, ingesting the spores of the bacteria is fatal as once inside the maggot a natural toxin is released by the activated bacteria spores.

"The first function of this is as a drench," Mr Hayes said.

Both the protein and the mechanism to release the toxin in the gut of the maggots are presently under a patent owned by Mr Hayes, who is looking for a manufacturer and a research arm to give the idea a chance.

"AWI had this for a year and I signed a confidentiality agreement with them, but the verbal understanding was that it was to be trialled at the end of 2006.

"I investigated and found out they had done nothing about it at all and refused to give any reason."

AWI stated that proposals were considered and assessed on the three key criteria of science, merit and the capacity to get the idea to market.

"While AWI must adhere to signed confidentiality agreements, the operating principle is that new ideas are assessed against key criteria and a judgment call is made, on behalf of woolgrowers," AWI said.

"Generally, if an idea or a product is good, it will attract a commercial partner quickly.

"AWI is not in the business of taking such products to market, that is the role of commercial partners.

"Proponents are always welcome to re-submit ideas for assessment under due process. AWI will contact Mr Hayes to facilitate this."

Roughly 80pc of the cotton now grown in Australia is 'Bt cotton'.