Rapid advances in the biological sciences promise much in the way of new therapies, but they may also bring us frightening new weapons.

Fears about the military use of such research have prompted the UK government to push for strict international controls.

Michael Williams explains the new controls required

More than 150 countries have signed the Biological Weapons Convention drawn up a quarter of a century ago, but it has not stopped some countries developing biological agents.

The Human Genome Project for example - which aims to map the landscape of the human genetic code - is an example of the giant leaps that are being made in this field.

But there are those who might use that knowledge to create appalling arsenals - potentially even to the point of creating biological agents capable of attacking only certain ethnic groups, using genetic differences to home in on the victims.

Foreign Office Minister Tony Lloyd says the Biological Weapons Convention needs to be strengthened to cope with rapid advances in knowledge and technology.

He says he believes the potential for new weapons is both "extraordinary and frightening".

Michael Moody: "a genuine strategic approach" is required

The UK Government says the Convention as it stands is powerless to stop a dangerous proliferation of new weapons.

Mr Lloyd says a new international treaty is now required to inspect suspect sites and to provide legal sanctions against those countries which persist in developing biological arsenals.

Call for strategic approach

Michael Moody, president of the Chemical Biological Arms Control Institute, believes that the task will demand a thorough and concerted international approach.

He said: "The problem of biological weapons is a complicated challenge, and it requires not just a single instrument to solve the problem but a variety of policy tools working together - arms control and strengthening the Convention are very important.

"But so are export controls, so are defence capabilities, so is our diplomatic effort and we're only really going to deal with the problem effectively if we integrate all of these possible tools into a genuine strategic approach."

The Biological Weapons Convention now has 159 signatories, among them Iran, Iraq, Libya and China.

Terrible threats

These are just a few of the nations also thought to possess or develop biological weapons.

Mr Moody: "we have to be reasonable"

The overwhelming majority of signatories differ on the complex details and there are major differences on the substance of the proposals.

Some countries object to the prospect of surprise inspections and many developing nations are more enthusiastic about taking advantage of provisions in the Convention which allow for biological information to be shared.

Since the mid-1970s, when research first offered the opportunity of genetic engineering, biological sciences have flourished.

They promised great benefits, but also encompassed terrible threats.

Biological weapons of the future might be engineered to make them more infective or longer-lasting.

Frightening potential

Some fear that toxins and diseases could be formulated to attack individuals or ethnic groups, using markers in their genetic code to target specific victims.

The British Medical Association is so concerned about the potential threats that it will soon publish its own study of the problem.

Vivian Nathanson, the BMA's head of science and health policy, says there is growing evidence that a number of countries are investigating new biological research for its weapons potential.

She believes the world must act to prevent their development before it is too late.