CHICAGO (CBS) — Five former Cook County Jail inmates are suing the Sheriff’s office.

As WBBM Newsradio’s Jan Coleman reports, the former inmates say they were locked up a day past their release date because of the Sheriff Department’s unreliable computer.

LISTEN: WBBM Newsradio’s Jan Coleman reports

The federal lawsuit they filed says the computer fails frequently and failed on March 16, 2009 — their scheduled release date.

The computer was not available for background checks to make sure the inmates did not have outstanding warrants or other cases against them, the lawsuit says. It was up and running the next day the background checks were done, the inmates were released, the suit says.

Sheriff’s office spokesman Frank Bilecki said he had not seen the lawsuit and could not comment directly on it.

Bilecki confirmed that jail officials conduct background checks before releasing inmates. In addition to looking for outstanding warrants, the checks also make sure the right person is being released, Bilecki said, adding that it is not uncommon for some inmates to have similiar names.

The suit is asking for unspecified damages.

The Sun-Times Media Wire contributed to this report.