Sala, 28, and pilot David Ibbotson, 59, crashed on 21 January while travelling from Nantes in France to Cardiff.
Toxicology tests on Sala’s body showed CO levels in his blood were so great it could have caused a seizure, unconsciousness or a heart attack.
The Sala family said there should be a detailed examination of the plane.
Mr Ibbotson, from Crowle, North Lincolnshire, has still not been found.
The Air Accidents Investigation Branch (AAIB) said Sala’s blood had a COHb (carboxyhaemoglobin – which forms in red blood cells upon contact with carbon monoxide) level of 58%.
At this level, symptoms would include include seizure, unconsciousness and heart attack.
Source: AFP
