A British Airways flight was delayed for several hours after women members of the Qatari royal family objected to sitting next to men they did not know.
The British Airways flight was destined for Heathrow airport
The three wives of Sheikh Badr Bin Khalifa al-Thani refused take up their seats on board Flight 563 from Milan's Linate airport to London Heathrow.
Police and Qatari diplomats became involved before the captain told Sheikh Badr's entourage to leave the aircraft.
The Qatari royals eventually ended up getting an Alitalia flight to London.
They had been on a shopping day-trip to the Italian city.
In addition to his three wives, Sheikh Badr, a junior member of Qatar's 3,000-strong ruling family, was accompanied by a male relative, a cook and another servant on the flight.
After boarding, the women complained about the seats they had been allocated because they were next to men they did not know, a spokesman at Linate said.
Cabin crew tried to move the passengers to different seats, but those travelling with other people refused to change.
Sheikh Badr then reportedly got up and walked to the pilot's cabin to complain.
A delay of nearly four hours ensued as two members of the Qatari party refused to sit down.
A BA spokesman said the captain eventually had no option but to return to the terminal.
"The people were offloaded because they failed to comply with safety instructions when the aircraft was taxiing," he said.
Later in the evening, the royals travelled business class with the Italian carrier, Alitalia, with their staff in economy.
The Qatar embassy in Rome said it was a "private matter".