Bioterrorists using commercially available technology and materials could, with relative ease, make a synthesized version of the polio virus, the Canadian military has warned.

"There are concerns that terrorists can now create viruses," says a military intelligence assessment obtained by Ottawa researcher Ken Rubin through the Access to Information Act.

"The production of a synthetic polio virus is relatively simple compared to the difficulties that would be faced attempting to synthesize larger and more complex viruses such as smallpox," says the July 2002 assessment.

It followed on the heels of an announcement by researchers at the State University of New York that they had assembled a man-made version of the polio virus from scratch, using DNA and a genetic blueprint for the pathogen available on the Internet. The genetic material used to build the virus came from supply houses that make the chemicals to order.

Though the technology has been available for years, the experiment marked the first time an artificial infectious virus has been created. The researchers said they carried out the experiment to show how easy it would be for terrorists to create deadly germs for biological weapons.

Polio once paralysed tens of thousands of children a year before vaccination made it a rare disease.

Canada arrested the spread of the disease in the 1970s and, since most adults in the world have now been immunized, it seems an artificial polio virus would pose little danger, except to, perhaps, unvaccinated children.

But far more dangerous pathogens to which people have little or no immunity, such as smallpox, Ebola or a novel and virulent influenza virus, could also be created the same way, though that would require more complex bioengineering, the American scientists warned.

The Canadian military agrees.

"The implication of the research is that a terrorist organization could do the same thing," says the intelligence assessment, titled Synthetic Viruses -- Biological Warfare Concern?

"There appears to be no practical method of limiting the flow of this type of technology, equipment and related materials; as such, none are specifically captured by Canada's export controls."