For the last two years the Senior Coroner for the County of Dorset has been investigating the death of a man called Richard Westgate.
Mr Westgate was a pilot for British Airways. He was on medical leave when he died, aged 43. He believed he had been poisoned by repeated exposure, during his career, to contaminated cabin air.
Sheriff Stanhope Payne has not finished his investigation, the inquest has not yet been heard, but he has written to British Airways and the Civil Aviation Authority to express concern about the evidence he's seen to date.
The coroner has sent them a report - we've obtained a copy - in which he says that in his opinion "there is a risk that future deaths will occur unless action is taken".
He lists his concerns, they are as follows:
1) That "organo-phosphate compounds" are present in aircraft cabin air
2) That people in aircraft cabins are exposed to them, with consequential damage to their health.
3) That impairments to the health of those controlling the aircraft - i.e. the pilots - may lead to the death of the occupants
4) That there is no real-time monitoring to detect such compounds in the cabin air.
5) That no account is taken of genetic variation in humans, such as would render individuals tolerant or intolerant of exposure.
The coroner calls for "urgent action". He gives the airline and the regulator 56 days to respond.
It is common practice in the airline industry to use warm, compressed air from aircraft engines to pressurise the cabin.
The Civil Aviation Authority (CAA) is responsible for monitoring and maintaining air quality on planes.
The CAA told ITV News that this report is "nothing that passengers or crew should be overly concerned about". It acknowledges that aerotoxic syndrome is a condition that exists but insists occurrences are rare.
The CAA said it has received the report and will be looking at it in detail and report back in due course.
British Airways said "we will respond to the coroner in due course. It would be inappropriate to comment further while proceedings are continuing."