British Airways is being sued by a holidaymaker who claims he was left badly injured after being forced to squeeze into a seat next to a passenger the size of rugby legend Jonah Lomu.
Stephen Prosser, 51, is suing the airline for £10,000 over his experience on a flight from Bangkok to Heathrow, which he says left him with a continual back spasm and an injury causing a joint at the bottom of his spine to dysfunction.
The Welshman told Pontypridd County Court how he immediately suspected there might be an issue with his neighbour on the 12-hour journey, with him described as being 6ft 4in and weighing around 22 stone.
Mr Prosser, who is 5ft 3in, said the man next to him was so large "that he had to force his buttocks between the arm rests of the seats".
He added: "I sat with his knees wedged against the seat in front and the rest of his body was over spilling into my seat by some inches.
"I was immediately aware that this was going to be problematic for me and I could feel the weight of his pure bulk putting lateral pressure on my upper body. This forced me into a position of unnatural posture.
"Due to the size of him when he placed his arm down at times it would rest on my armrest, and he would accidentally turn the volume of my audio up to an extremely loud volume each time."
The self-employed civil engineer said he raised his concerns with cabin crew but was told the Boeing 777 was fully booked and that there was no possibility of swapping seats with anyone.
He did not mention his discomfort to the passenger concerned, who he said seemed self-conscious, but denied he was taking dramatic liberty by comparing him to the late New Zealand hero, who died aged 40 in November 2015.
Timothy Salisbury, representing British Airways, said: "You say the man reminded you of the late rugby player Jonah Lomu. Would you say that's a colourful explanation? An exaggeration?"
Mr Prosser replied: "Not at all."
Lomu was 6ft 4in and weighed 19 stone.
Mr Salisbury said cabin crew on the January 2016 flight described the passenger as a tall man - "but not so overweight he had encroached on the other seat".
Chris McLindon, the customer service manager on board the flight, said in a witness statement that Mr Prosser did not seem to be in any discomfort and "at times he was asleep".
But Mr Prosser claims the unnatural position he was forced into during the flight aggravated a 12-year-old spine injury caused by driving long distances for work - leaving him unable to work overtime due to back pain.
He also claims that the injury and pain left him lacking energy, which affected his relationship with his partner and forced him to give up mountain biking.
The hearing continues.