Data Protection Commissioner Billy Hawkes has described as a "disturbing" development the proposed use of information from utility bills for the collection of the new household charge.
Owners of residential properties must pay the €100 charge by 31 March and should register their property by the beginning of March if setting up a direct debit.
Speaking on RTÉ's Morning Ireland, Mr Hawkes said any access to information from ESB or other bills should be minimal.
Mr Hawkes said the move was an extension of the powers of the State.
Minister for Local Government Phil Hogan has said this afternoon that the household charge website "adheres to the required data protection and privacy standards".
There were technical issues with the www.householdcharge.ie site yesterday, which caused people to make duplicate entries.
Mr Hogan said that any information provided to the website is "fully secure" and that any privacy issues will "be addressed immediately".
A meeting has been scheduled for next week between the minister's department and the commissioner's office to discuss the concerns over the sharing of information.
Minister Hogan said that 10,000 properties were registered on the website to pay the charge.
He said: "I would like to acknowledge and thank the 10,000 who have registered their properties and paid the charge at this early stage.
"The large numbers of people paying the charge is a clear indication of compliance with the legislation and the acceptance that the household charge is necessary to fund vital local services in our communities."
Mr Hawkes welcomed the statement from the Minister, but said he still has a "general issue" that the law provides for the State having access to information that is held by a commercial company.
He said there is an issue of proportionality given that the State has access to all the information held by the Revenue Commissioners, the Department of Social Protection and the Private Residential Tenancy Board.
He also said his office would agree with the Department the improvements that are necessary for providing people with information on the website including the justification for the need to provide a PPSN.