Campaigners fighting for victims of the Lowermoor water poisoning said the Government's long-awaited apology would be "meaningless" unless further action is taken.
On Thursday, Health Minister Anna Soubry and Environment Minister Richard Benyon made a joint apology for their department's failings in handling the incident which hit North Cornwall in the summer of 1988.
In a letter to Lib-Dem MP Dan Rogerson, the Ministers admitted there had been "failings in the response to the incident" but said "lessons" had been learned to better protect communities.
"However none of this takes away the distress and anguish felt by many of your constituents over the intervening 25 years," they said.
"In light of the findings of the various investigations into the Lowermoor water incident we, on behalf of Government, unreservedly apologise to your constituents."
It is the first time since the supply serving 20,000 people living from Boscastle down to Port Isaac was polluted, that victims, many of whom believe they have long-term conditions linked to the acid water poisoning, have received any kind of apology from Government.
The death of Carole Cross, 59, who died in 2004 from a rare neurological disease usually associated with Alzheimer's, was the first to be linked to the incident.
And her husband Doug said the apology had to be followed by further investigation.
"They are the first words of apology we have had and it is difficult to know if they are empty or half full," he said.
"But they will be meaningless if nothing else is done.
"There is the opportunity for a full investigation into the response at the time and the health of people who are genuinely concerned and for good reason."
Mr Cross believes there is scope for a criminal inquiry, echoing calls made by Mr Rogerson, into whether a cover-up was instigated to protect the water industry which was on the verge of being privatised.
Mr Rogerson said Devon and Cornwall Police should "re-open their investigation" and "should find no door closed in establishing whether and how a cover-up happened".
He said residents affected by the Lowermoor incident had "a right to know who made those mistakes and why".
Campaigners are also waiting to hear whether recommendations for further research into the long-term health affects of the pollution, caused when 20 tons of acidic cleansing agent were dumped directly into the supply at the Lowermoor water treatment works, will be taken forward by the Department of Health.
Devon and Cornwall Police said in a statement: "Devon and Cornwall Police await a formal request (for an investigation) and any decision on this matter would be taken at that time."