Employers are fitting out their fleets of company cars with invasive GPS tracking systems despite claims the technology unnecessarily invades staff privacy and contributed to the suicide of a Telstra linesman last year.

One such tracker, the GoFinder Reporter, sends employers detailed daily time sheets showing every stop made, parked time, driving time, distance covered, maximum speed and even an estimate of the amount of fuel used. Each location can be displayed on a street map or Google Earth.

The owner of a Sydney tree removal company, who did not wish to be named because he does not tell staff they are being monitored, said the device allowed him to assign jobs to his five workers spontaneously throughout the day.

It also ensured none of them accepted extra work on the side for cash without telling him. He did not believe he was being unethical or breaking the law.