THE RISK of a terrorist attack was wronglyusedbytheScottish Executive as an excuse to keep information about radioactive contamination of drinking water secret.

The Scottish information commissioner, Kevin Dunion, has found the Executive guilty of breaching freedom of information legislation by failing to provide documents from a file entitled "Release of radionuclides in drinking water systems".

TheSundayHeraldoriginally requested the documents in December 2005, and appealed to Dunion after they werewithheldbytheExecutive.The verdict of his investigation, received on Friday,isadamningindictmentof the official secrecy that persists in the Scottish civil service.

"A notable feature of this case is that the Executive has suggested release of this information may have dire consequences," Dunion said. "It has said that release could constitute an offence under anti-terrorism laws, that it might harm national security and it could even be misused in a way which could be lethal to the public."

Such claims, however, turned out to becompletelyunfounded,Dunion concluded."Afterconsideringthe nature and content of the information being withheld I found that not only are these highly worrying claims overstated, in fact it is not possible to find any justification for them at all," he said.

The Executive argued that releasing the documents would breach section 79 of the Anti-terrorism, Crime and Security Act 2001 because it "might prejudice the security of any nuclear site or of any nuclear material". But it failed to produce any evidence to back up its case.

According to Dunion, the six withheld documents are about "the financing and administrative arrangements involved in setting up a joint research project". They consist of "innocuous exchanges" with the UK government, he said.

Dunion pointed out that the government's Health Protection Agency had already published detailed guidance on how to respond to an attempt to poison drinking water with up to 23 different radionuclides. Authorities have been advised to draw up contingency plans, includingpossibletreatmentsand alternative sources of supply.

"If this kind of information is readily available,itisinconceivablethat disclosureoftheinformationwith- held by the Executive in this case could have the effect upon national security andpublicsafetywhichitalleges," Dunion said.

The Executive argued the documents should remain secret as their release could damage relations with the UK government, or inhibit the formulation of Scottish administrative policy. But both arguments were dismissed by Dunion.

He concluded that the Executive had incorrectly applied three sections of the Freedom of Information (Scotland) Act 2002, and was in breach of part one of the act. He has ordered the withheld documents to be released within 45 days.

AspokesmanfortheScottish Executive said: "We have just received thedecisionfromtheinformation commissioner on this case, which dates back to the previous administration, and are considering its terms. It would be premature to comment at this stage."