London, Jan 23: A leading toxicologist has said that there could be a "conspiracy or cock-up" over blood samples from Princess Diana's driver Henri Paul.

Toxicologist Prof Robert Forrest told the inquest into the late Princess’ death that was “very, very unlikely” that Mr Paul had a 20.7 per cent Carboxyhaemoglobin concentration in his blood at the time of the accident, as found in post mortem tests, reports the BBC.

He stated that the "biologically inexplicable" levels of carbon monoxide in Henri Paul's blood were "analytical error or a mystery" because if the late Paris Ritz security chief been exposed to such levels as the tests suggested, he should have been visibly ill.

Prof Forrest said that he had based his conclusion on CCTV footage that showed Henri Paul in the hotel on the night of the crash walking around, laughing, joking and even easily tying his shoelaces.

The inquest into Diana and Dodi’s death has already heard how tests found that Mr Paul was almost three times the French drink-drive limit at the time of the accident.

However, Dodi’s father Mohamed al Fayed is convinced the samples were switched to cover up a murder plot. (ANI)