But the existence of so many "phantom fonctionnaires" has shocked the nation at a time when French workers feel overburdened by what many see as excessive taxes and the high cost of living.
The audit office report was revealed by Var-Matin, a local newspaper, only two months after an Economy Ministry report revealed that more than 300,000 civil servants fail to fulfil their obligation to work 35 hours a week.
France's statutory working week is one of the shortest in the world, but many private-sector workers say they put in extra hours to achieve their targets.
President Emmanuel Macron has promised to shed 120,000 civil service jobs as part of a drive to cut €60 billion in public spending by 2022.
One of the 30 "fonctionnaires" paid for doing nothing, an administrative assistant, took a private-sector job as a manager for eight years while he continued to receive his civil service salary.
Others benefited from automatic promotions and pay increases based on seniority or length of service.
The audit office report noted that the Var management centre responsible for the "phantom" civil servants "had little motivation to find them new jobs" because, as long as it reported a deficit, the bulk of their salaries would continue to be paid out of the budgets of the local authorities that had originally employed them.
"The budget forecast of the management centre is presented showing a deficit each year to trigger a specific legal provision allowing continued funding of the remuneration of staff without jobs," the report said.
The audit office also criticised the "jobless" civil servants for maximising their pensions by remaining on the payroll until reaching the working-age limit of 67.
It is not the first case of public sector employees being paid for doing nothing in France.
In 2016, a senior civil servant was found to have claimed his monthly salary of nearly €4000 for 10 years without doing a day's work.
In another case, the state rail company, SNCF, paid a manager more than €5000 a month for 12 years although he was not working.
In 2016, a Spanish court fined a civil servant who had collected full pay for 14 years without going to his office.
Perhaps more surprisingly, Germany, with its reputation for efficiency, was embarrassed by the revelation in 2012 that a civil servant had been paid for 14 years without doing any work.