The revelations about the dumping of nuclear waste material in the Irish Sea have brought calls from environmental organisations for a comprehensive inquiry to determine how the British government could have misled the public for so long.

FOR 13 years British government ministers have repeatedly insisted that no radioactive waste was ever deposited in Beaufort Dyke. Such was their confidence in this assumption that officials denounced environmentalists as "scaremongers" for having the temerity to even suggest that departments may have authorised the dumping.

But later this week, a British government minister will finally publicly admit that the environmentalists were right all along. Secret official papers between the Scottish Office and the Ministry of Agriculture, Fisheries and Food (MAFF), dating back to the 1950s, have suddenly been "rediscovered". These state that up to two tonnes of radioactive waste was dumped in Beaufort Dyke.

It is believed that the papers, which were uncovered in the Public Records Office, will reveal that the Scottish Office authorised the dumping of the "low-level" waste from private companies, including the defence contractor Ferranti, during the 1950s and early 1960s. However, the British government still does not know the exact details of the materials dumped or the quantities.

"This is another piece of the jig-saw, but the problem is it may never be completed, and worse still we have absolutely no idea how big the jigsaw is yet," says Dr Paul Johnston, from Greenpeace's research unit at Exeter University.

Perhaps not surprisingly, environmental organisations have immediately demanded a comprehensive inquiry to examine why the British public was lied to for so many years. "Is it all part of a cover-up or did civil servants really not know the facts and so misled ministers? Or were these papers missed for political reasons?" asks Dr Richard Dixon, the head of research for Friends of the Earth in Scotland.

Environmentalists also fear that more secret British government papers, which may only be publicly released after 30, 50 or even 1OO years, will reveal the full extent of the cocktail of chemicals and radium dumped by the Ministry of Defence.

Dr Dixon believes that chemical and nerve gases such as anthrax and sarine, which was used in recent attacks on the Tokyo underground, may well have been dumped after the second World War. Even though the gases may have been sealed in metal drums encased in concrete, this casing will slowly degrade, enabling the poisons to leak into the sea.

"What has happened to all the German ammunitions which were seized after the war? And the Germans were experimenting with chemical and biological warfare. What happened to all that? The Ministry of Defence records have either been destroyed, are too vague, or are probably sitting in a filing cabinet somewhere waiting to be rediscovered. We need the full details now. This is literally a time bomb waiting to explode," Dr Dixon argues.

Beaufort Dyke is a deep depression 32 miles long and 15 metres wide, on the seabed between Northern Ireland and Scotland, where munitions were dumped between the 1920s and 1976. However, the scale of this hidden deposit has never been revealed by the British government.

Only last year a report commissioned by both the Irish and British governments confirmed that more weapons had been dumped than previously admitted and found that many had been deposited outside the designated area. Despite these revelations, ministers have repeatedly insisted that there is no danger to the public.

"There appears to be a drip-drip strategy, with new pieces of information suddenly being announced every year, which is immediately followed by an assurance that everything is perfectly safe. It is incredulous to believe this. Sea- dumping is very difficult to monitor or recover. How can they honestly say everything is perfectly safe? They simply don't know," Dr Johnston says

IN 1995, a British Geographical Survey of the area detected a number of "unexplained" underwater explosions, suspected to be hand-grenades blowing up, which caused thousands of highly- dangerous phosphorous flares to float ashore on the western Scottish and northern Irish coastlines. In one year alone 5,000 sticks were washed up in Scotland.

An estimated 1.17 million tonnes of conventional weapons and chemical weapons have been deposited in Beaufort Dyke. Workmen laying a British Gas pipeline to link Scotland and Northern Ireland reported detecting metallic objects on the sea bed close to the dump. They also reported underwater explosions, which prompted MAFF to order an investigation.

It is expected that MAFF will finally publish its seabed television survey later this week as a result of these latest revelations. According to Dr Johnston, the preliminary results have shown some evidence of contamination. "This survey has been ready for nearly two years, so why the delay? I suspect they have been scratching their heads trying to work out the least controversial spin for all this data," he said.