ALBANY, N.Y. - The New York Civil Liberties Union has sued the state on behalf of a labor-department worker who was fired after investigators used a global-positioning system to track his car and show that he had falsified his time sheets.

Since that 2008 investigation, New York's highest court has struck down the state police's use of a GPS to track suspects unless officers get a warrant. That ruling overturned two lower court decisions.

The new lawsuit announced yesterday said that use of the electronic device on Michael Cunningham's personal car was unconstitutional and too intrusive to be justified by the limited-warrant exception for searches of government employees.

"Our argument is that even under the lower standard this is clearly an unconstitutional search," NYCLU attorney Corey Stoughton said.

Cunningham was fired in August after a hearing officer concluded that he had claimed pay for hours when he wasn't working. He countered that the charges were unproven and that the GPS information was flawed.

The state's case included investigator accounts and records, but relied heavily on the GPS data.

The lawsuit seeks a declaration from the state Department of Labor that putting the GPS tracker on Cunningham's family car was a violation of the state constitution's guarantee against unreasonable searches and seizures. It also wants the hearing officer's decision thrown out and Cunningham returned to his job as director of the Office of Staff and Organizational Development at the department, a post he held for 22 years.

The labor department stood by the firing.

"While we cannot comment on the litigation," department spokesman Leo Rosales said yesterday, "we can reiterate what has been said in the past regarding this case: After multiple disciplinary actions, Mr. Cunningham was found by an independent hearing officer to have defrauded New Yorkers by falsifying time and attendance and travel records which ultimately led to his termination for cause."