French actor Gerard Depardieu has apologised for the "humiliating" incident which saw him removed from a flight to Dublin, a friend said.
Depardieu, 62, urinated in front of fellow passengers after being refused permission to use the lavatory as the plane prepared for take-off.
Staff told him to stay seated but it is understood he urinated into a bottle.
Fellow actor Edouard Baer, travelling with him, said his friend had prostate problems and had not been drinking.
After being removed from the flight, Depardieu caught a later flight to Dublin.
He was flying to Ireland with Cityjet to film Asterix and Obelix: God Save Britannia.
In a statement issued on Depardieu's behalf to French media, Baer said he had passed him the bottle in which to urinate, but it had overflowed.
"Gerard was upset at this and offered to clean up the mess," he said.
"He has prostate problems and it was very worrying and humiliating for him.
"He was also stone-cold sober at the time. This is not the way he usually behaves."
A passenger on the CityJet plane contacted a French radio station on Wednesday and to say that Depardieu had stood up minutes before take-off and declared in a loud voice: "Je veux pisser, je veux pisser" (English: I want to pee).
Following the incident, the aircraft taxied back to the terminal at Charles de Gaulle airport and Depardieu was removed from the flight.
Cityjet confirmed the plane had been delayed and it took off later than scheduled.
In a statement the airline, a subsidiary of Air France, said: "Flight AF5010, which was due to depart at 1845 from Paris to Dublin, was delayed due to an incident on board involving a passenger who refused to remain in his seat as the aircraft was taxiing on the runway.
"The captain returned the aircraft to stand where the passenger was offloaded."