Heathrow is investigating claims that a terminally ill boy was forced to lie on the floor for several hours as his family waited to change aircraft.

Nahuel Matias Santucho was travelling with his family to Buenos Aires to spend the “last days of life” with relatives in Argentina on September 13.

The family arrived at the London airport from Warsaw but missed their connecting flight and the 15 year old had to be “nursed on the floor”.

Nahuel, who breathes via a tube in his windpipe, suffers from an incurable disease that affects his brain and spinal cord.

He was travelling with his parents, brother, sister and a medical escort when their flight from Poland was delayed and arrived late.

His mother Andrea Lopez said it then took 45 minutes to leave the aircraft because of a problem with a lift.

They were expecting to be taken to their aircraft to Argentina from Terminal 5 but “this never happened” and they were instead taken to a locked corridor with Nahuel having to sit in a “very narrow and uncomfortable wheelchair”.

She said her son “started to moan and show evident signals of tiredness and discomfort” so was moved to the floor for him to be seen by a paramedic, the BBC reported.

After “several hours” a British Airways employee then arranged for the family to be taken to a nearby hotel and rebooked on a flight the following day.

A Heathrow spokesman said it was “clearly a distressing time… for which we are sorry”.

Initial investigations had found “Napu’s own wheelchair was not available once he left the aircraft and he was uncomfortable in the replacement wheelchair” so was moved to the floor.

“We continue to work with all parties involved to find out all the detail of what happened and how his journey could have been made more comfortable,” the spokesman said.

A BA spokesman said the airline had “provided hotel accommodation” and “arranged for a doctor to provide suitable food” but it would “continue to investigate with Heathrow airport and their wheelchair provider”.