"It is unfortunate that the state had to take such action, which led to the inevitable inconvenience of the 149 passengers onboard the immobilised plane", the French civil aviation authority said.
The Associated Press contribute to this report.
Travelers were left out of the loop for most of the ordeal, with only two text messages telling them that the departure was delayed and that they would receive vouchers worth about $6 for food.
"I found it odd that the police were the only ones giving us information", he said.
DGAC said 149 passengers were put on another flight on Thursday evening and arrived at their destination five hours late.
France is demanding the Irish airline hand back money paid by the small airport of Angulema-Cognac to Ryanair between 2008 and 2009.
The budget airline's plane would remain grounded "until the sum is paid", France's aviation authority said. A final legal warning was sent in May, but after six months without a response from Ryanair, it was time to act. Charente officials claim that Ryanair owes them the equivalent of just over £450,000, having paid back half of the subsidies.
Ryanair has become Europe's largest airline by number of passengers by persistently offering some of the cheapest fares available.
The budget airliner is known in Europe for its low-priced flight tickets, achieved with the aid of add-on fares including food and carry-ons larger than a purse.
It manages to keep its costs down by flying to out of the way airports at odd hours to get cheaper airport slots.
Thursday's incident tops a recent list of problems for Ryanair, including flight cancellations because of problems within the company. "When we found out about the seizure, I would say the general sentiment was to blame Ryanair for not complying with the law".