Christine Ahmed awoke after her long nap presuming that she had arrived at her destination at Paris' Charles de Gaulle airport only to realise that the passengers and crew had changed, and that she was heading back to Asia.

The flight left Lahore on Tuesday midday heading for Paris via Milan, bringing the woman all the way back to Lahore on Wednesday morning.

Pakistan International Airlines (PIA) has now launched an investigation into how ground crew failed to noticed that the woman remained on board during the two-hour stopover in Paris.

According to the airline the situation was not brought to the attention of the crew and immigration officials at Lahore airport were the first to notice the mishap.

The woman, who is married to a Pakistani, was put on a new flight on Wednesday with another carrier as PIA did not have anything available.

The issue of the cost of the new ticket to Paris remained unresolved however, with the airline unwilling to foot the bill.

"It is the responsibility of the passengers to get off the plane," PIA spokesperson Sultan Hassan told the AFP news agency.