Michael Quinn said the agency's voter information systems manager accidentally included information such as driver's licence numbers, birthdates and in some cases phone numbers with the annual voters list.
"This is a regrettable situation but it is simply human error," Quinn told a news conference.
Ron Armitage, the voter information systems manager, said he takes full responsibility for what happened.
"I take the integrity of individual privacy very seriously and I deeply regret having made this error," Armitage said.
"I take full responsibility and feel badly that it occurred."
Information belonging to 553,000 voters was distributed to the province's 55 legislature members and the Liberal and Progressive Conservative parties between April 3 and May 1. But the problem was only discovered Tuesday afternoon when the executive assistant to the economic development minister opened a disc on his computer, said Premier David Alward, who announced the breach earlier in the day in the legislature.
"This amounts to an accidental but nonetheless a serious departure of proper procedure," the Tory premier said.
"Driver's licence numbers, dates of birth and telephone numbers are not authorized for disclosure to members of the legislative assembly and as such, disclosure is a violation of the privacy of individuals involved."
Alward called for an investigation.
"This is not a question of embarrassment," Alward said. "This is a question of realizing that there were actions that took place that are not acceptable."
Quinn said he expects his office will be able to retrieve all discs containing the information within the next few days and promised to file a report on what happened with the Speaker of the legislature.
Alward and Liberal Opposition Leader Victor Boudreau said their members will co-operate with the recovery of information.
"I have directed all members of our caucus and our party office to return every single copy of recently distributed discs containing a list of electors to the chief electoral office," Boudreau said.
"I will also instruct those who have received the disc to erase any copies of these discs if they had been made."
The breach comes as Elections New Brunswick prepares for municipal elections next week, but Quinn said an increased workload was not to blame for the mistake.
"In the future, we will have a second set of eyes review those CDs before they go out," he said.
Members of the legislature are supposed to be given the voters list for their respective ridings, while the political parties are given a full list for the province.
The Elections Act says the lists may only contain the name, sex, address and mailing address for each eligible voter.