Montgomery County suspended its two chief election officials Wednesday, saying they intentionally deceived county officials throughout a recent probe into voter registration irregularities.

Voter Services Director Joseph Passarella was placed on unpaid leave for two days in a unanimous decision by the county's Election Board. His assistant, Patricia Allen, received a one-day suspension.

Board Chair Joseph M. Hoeffel III called their handling of the investigation unfortunate and vowed a "top-to-bottom" review of policies in Passarella's office.

"We were misled," he said.

Passarella and Allen, who were not at Wednesday's meeting, could not be reached for comment later.

The pair has been in the hot seat for weeks, since a Pennsylvania Department of State investigation blamed their office for improperly registering as many as 3,200 people to vote without their knowledge over three years.

An Inquirer story questioning a sharp rise in the number of Montgomery County voters registering as independents prompted that probe.

Nearly half the county's 30,000 new voters since 2009 have shown up on voter rolls as unaffiliated or associated with a minor party - a good deal more than in any other county in the state.

By comparison, such voters account for fewer than 29 percent of new registrants in Philadelphia, Bucks, Chester and Delaware Counties.

Passarella conceded last week that state officials had notified him in early May that "human error" by one of his employees was to blame for the disparity. But both he and Allen subsequently appeared before the Election Board and failed to mention those findings.

The panel only learned of Montgomery County's role after the State Department put out a news release four days before the May 17 primary publicly pointing the finger.

"I'm not trying to make excuses," Passarella told the board at a special hearing last week. "As the head of the department, it was my responsibility to know what was going on."

The problem arose in early 2008, he said, when a low-level Voter Services staffer began entering change-of-address forms from the Pennsylvania Department of Transportation's motor-voter system as new independent voter registrations.

The computer kiosks available at PennDot centers throughout the state allow people to change addresses on their driver's licenses and voter registrations at the same time.

For those already registered to vote, the system works fine.

However, counties also receive a list of those who attempt to update their addresses but were never originally registered to vote in the first place. The state asks local election offices to discard these.

The Montgomery County worker - who has not been publicly named - did not.

Still, Hoeffel said Wednesday, the mix-up caused no harm. No one was disenfranchised by the mistake and at worst, thousands of new county residents could have cast a ballot whether they knew it or not.

The problem remained rooted with the department's leadership for failing to realize the issue for three years or - once it knew - to immediately advise the Election Board, he said.

"The mistakes made were well-intended by people who acted in good faith," said Hoeffel. "No improper motives were uncovered."

Contact staff writer Jeremy Roebuck at 267-564-5218, jroebuck@phillynews.com, or @inqmontco on Twitter. Read his blog, "MontCo Memo," at www.philly.com/montcomemo