A former IT system auditor for a US government agency faces a five-year prison sentence on a computer hacking charge after secretly monitoring his supervisor's e-mail and computer use, the U.S. Department of Justice (DOJ) said.

Kenneth Kwak, 34, of Chantilly, Virginia, pleaded guilty Wednesday in U.S. District Court for the District of Columbia to unauthorized access to a protected computer in furtherance of a criminal or tortious act, the DOJ said.

Kwak was a system auditor working on federal information security management audits as a member of the U.S. Department of Education's Office of Inspector General. Kwak placed software on his supervisor's computer enabling him to access the computer's storage at will, the DOJ said.

Kwak later used that software on numerous occasions to view his supervisor's e-mail and Internet activity as well as other communications, and he shared those communications with others in his office, the DOJ said.

Kwak, who faces a maximum sentence of five years in prison and a US$250,000 fine, monitored the communications for personal entertainment, and there is no indication he profited financially from his actions, the DOJ said.

The case highlights the DOJ's "zero-tolerance approach to public corruption and computer hacking," U.S. Attorney Kenneth Wainstein said in a statement. Wainstein is U.S. attorney for the District of Columbia.