French authorities have seized a Ryanair plane at Bordeaux airport in a dispute over money they say the Irish airline owes.
The civil aviation authority grounded the Boeing 737 on Thursday, with the flight due to carry 149 passengers to Stansted.
The row involves money the airline received as aid related to its activities at the regional airport of Angouleme between 2008 and 2009, which the European Commission have since deemed illegal.
"It is unfortunate that the state had to take such action, which led to the inevitable inconvenience of the 149 passengers on board the immobilised plane," the French civil aviation authority said.
"Those passengers were able to eventually reach their destination later that evening on another Ryanair plane, but with a five-hour delay."
The authority did not specify the amount owed by Ryanair, but regional airport officials have said it is €525,000 (£457,000).
It continues what has been a turbulent autumn for the airline.
In October, Ryanair warned on full-year profits in the wake of a surge in the oil price and disruption caused by strikes. While it has reached deals with several unions, it faces resistance from staff in a number of countries.
The European Commission in October opened an investigation into whether Ryanair had benefited from illegal state aid at Germany's Frankfurt-Hahn airport, and this week Italy's antitrust agency opened a probe against Ryanair's new hand luggage policies.