Library picture: Heathrow Airport
A plane was stopped on the runway at Heathrow minutes before take-off after reports a child had been abducted.
The aircraft was due to fly to Bucharest.
Police stopped the plane and a 32-year-old man was arrested.
He has been released on police bail, with conditions, pending further enquiries.
It is alleged he had taken a four-year-old girl from her mother.
She was later returned to her home in Nottinghamshire.
The man is known to the mother and child.
Detective Sergeant Ruth Walker is leading the investigation.
She said: “When the report came in it was a race against the clock to find them.
“Using intelligence techniques and automatic number plate recognition cameras to help to trace and track down the car we identified he was at Heathrow airport.
“We did some border checks there to pinpoint which flight he was booked on to.
“We got the phone call at 4.57pm and they were due to fly at 6pm. It was due to take off and it was stopped on the runway.
“This was fantastic work by a whole host of officers and detectives across multi-agencies from Nottinghamshire and the Met Police.
“The plane was taxiing ready for take-off, but we were able to get there just in time before it took flight.
“The plane then returned to the terminal and the man was arrested.
“This was a hugely complex and challenging case, with its obvious pressures.
“I’d like to praise the team of detectives for their commitment and dedication to the investigation.
“If it wasn’t for the swift coordinated multi-agency response there may have been a very different outcome.”