The employee, 43-year-old Terry Childs, was arrested Sunday. He gave some passwords to police, which did not work, and refused to reveal the real code, the paper reported.

The new FiberWAN (Wide Area Network) handles city payroll files, jail bookings, law enforcement documents and official e-mail for San Francisco. The network is functioning but administrators have little or no access.

Harris said it's unknown why Childs tampered with the system. The Chronicle, however, reported that Childs was disciplined recently for poor performance. Childs worked in the Department of Technology for San Francisco, making close to US$150,000 a year, the paper reported.