A shadowy republican group issued a threat in 1999 to poison UK water supplies with a commonly available weedkiller. Both UK and Irish officials suspected it was a ruse by loyalist groups to smear republican paramilitaries.
The revelation came in secret documents released as part of the State Papers by the National Archive.
Documents revealed that the sinister threat was taken very seriously by the UK authorities. After they consulted with various experts, they were stunned to be told that such a contamination threat was technically possible.
Secret papers confirmed that the threat to UK water supplies was issued by a group calling itself the Republican Revenge Group (RRG).
It was unclear who precisely was involved in the RRG or if it had the means to carry out the threatened attacks. RRG had issued the threat via letters which were posted to the British embassy and to the Papal Nunciature in Dublin.
The letters were posted in June 1999 and threatened to proceed with the contamination of selected water supplies if London did not indicate its intention to withdraw from Northern Ireland.
In the letter, the group outlined that it planned to introduce weedkiller into selected water schemes across the UK, potentially causing thousands of people to get sick or even die.
RRG even went so far as to explain how it intended to contaminate the water supply systems.
The group said it would take a commonly available weedkiller and attach it to fire hydrants.
This would, by force of water pressure, introduce it into the water distribution system. Without a prior warning, it was feared the chemical would be introduced into the drinking water systems for tens of thousands of homes before the alarm could be raised.
RRG warned Britain it faced a new improvised chemical weapon.
However, both UK and Irish officials noted that the letters consistently used the phrase “HMG” for her majesty’s government.
British embassy officials in Dublin – the secret documents revealed – felt that no republican group would ever use such a phrase given their disdain for British royalty and empire.
One official suspected the letter could form part of a dirty tricks campaign by loyalists to damage their republican rivals particularly through the international media coverage of such a drinking water scare.
The letter was, another official noted, both cohesive and literate.
It was also found to have technical knowledge about how a water supply could be targeted.
The threat was taken seriously and UK officials were shocked to be told such a water poisoning was technically feasible.
To avoid widespread panic and to prevent the so-called RRG group from gaining a profile, the British government arranged a special media briefing.
Those called to the meeting included The Irish Independent, The Irish Times and RTÉ.
Publications were asked not to report on the story given the threat of public panic and the concern that, ultimately, the story might well prove to be a hoax.
UK officials promised to keep the media informed on developments and if any further correspondence indicated that the threat was real.
Gardaí had been briefed on the matter and, after a co-operative investigation with British police, identified a potential suspect for the threatening letters.
The man was from Scotland and had served as a soldier.
He was then living now resident in Dublin and was viewed as living in a fantasy world at times.
While the man was investigated, no prosecution was ever mounted.