The revelation, which follows the adjournment of an inquest on one of the victims after the coroner became concerned that the victim may have been poisoned, will refocus attention on the twin scandals of the original incident and the subsequent cover-up.
Carole Cross died after years of illness that followed taking a bath in water heavily polluted by aluminium sulphate, which was poured into the water supply of the small Cornish town of Camelford in 1988.
High levels of aluminium were found in parts of her brain, and a scientific paper due to be published soon is expected to confirm that her death appears to be linked to the incident.
Campaigners believe that more of the 20,000 people exposed to the polluted water have died as a result. Other victims with similar symptoms to Mrs Cross fear that they may follow her to the grave. One severely affected woman has already committed suicide.
The tragedy began when a driver poured 20 tons of the highly caustic chemical into the wrong tank at the Lowermoor water treatment works that serves the town. This caused "massive and almost instantaneous contamination of the water supply". Residents sounded the alarm after drinking or bathing in the foul-tasting water and after suffering weird effects that included skin peeling off their backs, hands and lips sticking together and fingernails and hair turning blue.
Official evidence obtained by the IoS shows that levels of aluminium reached 5,000 times the safety limit.
Yet the South West Water Authority, which then ran the works, was slow to investigate the cause of the problem and continued to insist that the water was safe to drink. Confidential documents show that the authority and the Conservative government were deeply concerned that the incident would endanger the then impending water privatisation.
Hundreds of people complained of skin burns, rashes, ulcers, sore mouths and joints, memory loss and other symptoms , which they attributed to the aluminium and other metals that the chemical had dissolved from supply pipes.
Their complaints were dismissed after controversial inquiries held by the water authority and by the Department of Health. But research published by the British Medical Journal concluded that the "poisoning probably led to long-term cerebral impairment in some people in Camelford".
The authority was prosecuted, but merely fined £10,000, and paid out just £400,000 in compensation, shared between 148 victims.
Campaigners now hope that the increasing evidence that Mrs Cross died from a strange disease as a result of the pollution will reawaken public concern.
Doug Cross, her husband, believes that 20 other people have died as a result of the disaster and that more cases are emerging. He says experts said at the time it would take 20 years for the effects to be known, adding: "It is now nearly 20 years."
Graham Sillifant says his wife, Sarah, who was in her twenties when she was exposed to the water, hanged herself last year after suffering dementia and other similar symptoms to Mrs Cross. He said yesterday: "It could well have been the water that was to blame."
Labour MP Michael Meacher, who visited Camelford as environment minister, calls the incident and its aftermath "a most unbelievable scandal".
South West Water, which succeeded the old authority after privatisation, says it has "nothing further to add to the already comprehensive detail available on the issue".
JOAN KING'S STORY
Three months after Joan King drank the water she started to experience "very peculiar imperfections" in her speech. She now finds itdifficult to concentrate, and has other Alzheimer's-like symptoms. When tired, she says, "I get so frustrated and because I can't express myself, I gather, I get almost unbearable". Her husband, Roger, says that though a normally peaceful person she becomes virtually uncontrollable. Tests have revealed high concentrations of aluminium in her fingernails and toenails. She says: "I was a metallurgist. But here I am now - half a person mentally."
CAROLE CROSS'S STORY
Doug Cross, above, and his wife, Carole, avoided drinking the water after spotting that there was something wrong with it while making a cup of tea. But Carole had a bath in it, and the water turned bright blue. She developed eczema and sore joints and found it difficult to raise her arms above her shoulders. An artist, she had to give up her work as Alzheimer's-like symptoms rapidly increased. Eventually, she became unable to speak or eat, and died. A post-mortem found high concentrations of aluminium in her brain, in different patterns from those usual for Alzheimer's victims.Reuse content