Pearse Doherty requested all documentation related to the cost of abolishing of the utility
A Sinn Féin TD has claimed that Irish Water's estimate that it would cost around €100 million to abolish the utility was 'plucked from the air'.
The utility is reported to have provided the estimated cost of abolition in response to media queries.
Pearse Doherty submitted a Freedom of Information requesting all documentation and correspondence in relation to the cost of abolition.
Deputy Doherty told Newstalk.com: "We found that, in relation to the cost that they had told the media, there isn't a shred of paper - not an email, not a back of the envelope calculation - to actually back up this guesstimate.
"[It was] a figure that was obviously just plucked from the air by whichever spokesperson was briefing the media," he said.
He explained that he would have expected to see a 'raft of documentation' that would have gone into great detail over the cost of abolition. "None of that actually exists," he added.
The Donegal TD suggested Irish Water's claimed marked 'desperate self-preservation' by the utility, in an attempt to 'scare the public away' from party's campaigning for the company's abolition.
The Environment Minister Simon Coveney last week explained that once-off costs - such as staff redundancies and the transition to another charging model - for the abolition of Irish Water could range from between €85 million and €169 million.
"In addition, some €1.6bn additional running and capital costs would arise over the period of the current Irish Water business plan to 2021," Minister Coveney added.
Deputy Doherty said that from his party's point of view, the cost of abolishing Irish Water would be 'negligible'.
"We would be setting up a new utility that wouldn't have water metering, that wouldn't have water charging for domestic customers, but would still continue with the expertise that has been garnered within the service," he said.