VANCOUVER -- The union representing postal workers wants Canada Post to release the number of community mailboxes that have been broken into across the country.

Mike Palecek, national president of the Canadian Union of Postal Workers, said he's frustrated by the Crown corporation's unwillingness to share how frequently mail theft occurs.

"We know it's a problem and we know it's a big problem," Palecek said Monday in an interview. "We're trying to find out how big so we can look for solutions."

The union has campaigned for the restoration of door-to-door service since the former Conservative government announced in 2013 it would be cutting the service. The Liberals campaigned in the last federal election to restore home delivery, and the results of a review into the future of Canada Post are expected to be released later this year.

Palecek said that while exact numbers are unavailable, anecdotal reports from postal workers indicate that mail sent to between 1,500 and 4,000 addresses in Richmond, B.C., is being held.

That could be for a variety of reasons, including break-ins to apartment panels or damaged community mailboxes, he said.

"We're just trying to know what we're dealing with here. This should be a simple question."

Canada Post spokesman Jon Hamilton disputed the union's claims, saying there are only 1,000 townhomes in Richmond that are without postal service, and none of them receive mail via community mailboxes.

All of those addresses are part of a single development where private mailboxes were vandalized and have yet to be repaired, he said, adding that the boxes are the responsibility of the residents association.

"We take security of the mail very seriously," Hamilton said, adding that Canada Post does not release statistics on mailbox theft or vandalism because of security concerns.

"We work with police so there's no secret. It's just we don't provide those publicly."

Canada Post doesn't want to encourage thefts and doesn't discuss security measures it puts in place, he said.

Home delivery started to be phased out in 2015, but the Liberals stopped the process pending the review of Canada Post's operations.