A stowaway has been found dead inside a jumbo jet after it touched down at Heathrow Airport.
The body of the man was discovered on Thursday morning in the landing gear bay of the British Airways Boeing 747 after a 6,000-mile (9,656 km) flight from Cape Town, the airline said.
Police said the man was not a passenger or a member of the crew on the flight from South Africa's second busiest airport.
Authorities in South Africa said a man was spotted jumping over a fence at the transport hub before running towards a BA flight as it waited to take off on Wednesday night.
Security staff gave chase but backed off for safety reasons and a subsequent search of the airport failed to find the man.
Airports Company South Africa, which runs the airport, said it was carrying out an investigation.
A spokeswoman said: "Last night at approximately 8.40pm a person was detected scaling the perimeter fence at Cape Town International Airport (CTIA).
"The airport immediately responded and, as a security patrol officer attempted to apprehend the man, he ran in the direction of a British Airways aircraft already in its holding pattern ready for take-off.
"For safety reasons the security officer could not approach the aircraft. A search of the airfield was immediately conducted but the person was not found.
"British Airways, in addition to various other parties, were notified. Further sweeps were conducted of the runway and the broader airfield.
"This morning, reports from London's Heathrow Airport confirmed that a stowaway was found on board a British Airways aircraft. The person was found dead.
"Airports Company South Africa is concerned about the loss of life and thus views this incident in the utmost serious light.
"A full investigation will be undertaken."
The Metropolitan Police said they were called to the scene at 6.25am along with paramedics and the man was confirmed dead shortly after 7am.
"The death is being treated as non-suspicious. Inquiries are ongoing to establish the man's identity," a spokesman said.
British Airways confirmed the body was found inside the landing gear bay of a Boeing 747, which can carry 345 passengers and has a top speed of 614mph (988kph).
They can fly at heights of up to 45,000ft (13,716m).
A British Airways spokesman said: "This is a very rare and sad event and our thoughts are with the individual's family."