A man has been arrested on suspicion of child abduction after police stopped a plane flying to Romania.
Nottinghamshire Police said they tracked down a man to Heathrow Airport after receiving a report that a four-year-old girl had been taken.
They received a call at 16:57 GMT Thursday, and the flight to Bucharest was due to take off at 18:00.
The 32-year-old is known to the girl, who has been reunited with her mother, a spokesman said.
Det Sgt Ruth Walker said it was “a hugely complex and challenging case”, and thanked officers from the Metropolitan Police for their assistance.
“The plane was taxiing ready for take-off, but we were able to get there just in time before it took flight,” she said.
“[It] then returned to the terminal and the man was arrested.
“If it wasn’t for the swift coordinated multi-agency response there may have been a very different outcome.”