French authorities have opened an investigation after a four year old girl was found hidden in a bag belonging to a passenger on board an Air France plane.

The French company says in a statement that the child, who traveled with "an adult" on Air France Flight 1891 from Istanbul to Paris on Monday, did not have a valid ticket.

Air France says it requested "the presence of French authorities on the flight's arrival" to deal with the matter.

Meanwhile other news sources say the woman was a resident of France who was in the process of adopting the child, from Haiti.

The woman was in the transit zone in Istanbul but was preventing from boarding her flight with the child. She then bought a new flight ticket and hid the child in a bag, according to the AFP.

“Once on board, she placed the child at her feet under a blanket, but the girl needed to go to the toilet and was noticed by other passengers, the source said.

The airline notified the French authorities but prosecutors decided not to press charges.