The FBI (search) said Friday it has shut down an e-mail system that it uses to communicate with the public because of a possible security breach.

The bureau is investigating whether someone hacked into the www.fbi.gov e-mail system, which is run by a private company, officials said.

"We use these accounts to communicate with you folks, view internet sites, and conduct other non-sensitive bureau business such as sending out press releases," Special Agent Steve Lazarus, the FBI's media coordinator in Atlanta, said in an e-mail describing the problem.

The FBI computer system that is used for case files, classified and sensitive information, and internal communications is unaffected, Lazarus said.

The bureau is in the process of switching its e-mail accounts, officials said.

Lawmakers and the Justice Department's inspector general have criticized the FBI for taking too much time and spending too much money to upgrade its computer systems. A $170 million project, Virtual Case File (search), may have to be scrapped because it is outdated and inadequate, FBI Director Robert Mueller (search) acknowledged Thursday in testimony on Capitol Hill.