The accusation comes on the heels of warnings issued by the U.S. Postal Service that thefts from mailboxes are increasing and that residents should not leave mail with personal or financial information in their home mailbox but take it instead to collection boxes or a post office.

Postal Inspector Kathryn M. Derwey confirmed that the employee, a man with 20 years of experience, has been placed on unpaid emergency suspension as the investigation continues.

Derwey said the evidence so far supports a "guess" that the thefts have been going on for a year or more, but she declined to disclose how the thefts came to light or other details of the investigation because the employee hasn't been arrested.

However, she said allegations of thefts by postal workers occur rarely in Hawai'i and generally have involved temporary workers, not long-term employees.

"We have very few incidents like this in Hawai'i, we're very lucky," Derwey said.

"You hear of this happening in New York, or Chicago. And it's very rare that we get a 20-year employee involved in something."

Derwey said prospective employees are given rigorous background checks, and if they become involved in activities resulting in arrest or conviction, they become open again to scrutiny.

"We can't have anything that would sully the reputation of the postal service or cast shadows on its integrity," she said. "I hope you put in that 99.9 percent of employees are trustworthy and honest and wouldn't take anything."