A coastguard aircraft involved in a fatal collision at Tokyo`s Haneda airport was not cleared for take-off, said BBC quoting Japanese authorities.
The smaller aeroplane collided with a Japan Airlines (JAL) passenger jet on the runway on Tuesday.
Newly released transcripts of air traffic control instructions just before the crash confirmed the JAL Airbus A350 was cleared to land.
Permission for take-off was not given to the coastguard Bombardier Dash-8.
According to officials, the JAL flight was cleared to land on runway 34R at Haneda while the coastguard aircraft was told to "taxi to holding point C5" - a place on the airfield`s taxiway system where aircraft await permission to enter the active runway for take-off.
The transcript shows the coastguard aircraft acknowledged the call from air traffic to taxi to the holding point - its last transmission before the collision.
The transcripts appear to contradict the coastguard plane`s captain - the only one of the six crew to survive - who told investigators he had been given permission to enter the runway which the JAL airliner was approaching.
All 379 passengers and crew on board the state of the art JAL Airbus were safely evacuated after the collision, police said.
Japan Airlines Flight 516 had departed from Sapporo`s New Chitose airport at 16:00 local time (07:00 GMT) and landed at Haneda shortly before 18:00.
Flames engulfed the airliner shortly after it landed.
"I felt a boom like we had hit something and jerked upward the moment we landed," one passenger told Kyodo news agency. "I saw sparks outside the window and the cabin filled with gas and smoke."
Passengers escaped via evacuation slides and ran to safety, footage and photos showed.
TV footage showed several fire engines at the scene as smoke and flames billowed from the Airbus. Footage from inside the aircraft showed passengers surrounded by thick smoke.
One woman posted a picture of a huge crowd watching the scene unfold. "I was on board. I`m safe. Thank goodness," she wrote on X, the platform formerly known as Twitter.
Officials said the flight crew had reported no problems before landing.
A statement from JAL said flight JL516 had been "involved in a collision with a Japan coastguard aircraft during its landing at Haneda Airport, resulting in a fire on the runway".
The coastguard aircraft was heading to help with rescue and relief efforts following Monday`s earthquake in Ishikawa. It was one of four aircraft on a mission to the quake site.
Within hours of the blaze, Tokyo police confirmed reports that five coastguard crew members had died and the pilot was severely injured.
Japan`s Prime Minister Fumio Kishida said the authorities were trying to make sure the accident did not impede deliveries of earthquake relief supplies.
"This is a great regret as the crew members performed their duties with a strong sense of mission and responsibility for the victims of the disaster area," he said.
At least 14 of the passengers and crew who were taken off the JAL flight suffered minor injuries, according to Japanese public broadcaster NHK, citing fire officials.
It is the first major accident involving an Airbus A350, one of a new breed of aircraft built largely of advanced materials such as carbon fibre-reinforced plastic.
The aircraft manufacturer is sending a team of specialists to assist in the investigation in Japan.
