'Doubts' over Paul's blood samples

Toxicologist Professor Robert Forrest said "biologically inexplicable" levels of carbon monoxide in Henri Paul's blood could either be seen as an "analytical error or a mystery".

Had the Paris Ritz security chief been exposed to the levels of the gas the tests suggested, he ought to have been visibly ill, Prof Robert Forrest told the court.

There was also no trace of two types of medication Mr Paul is thought to have been taking - including one for worms - found in the blood samples, the jury heard.

Prof Forrest said he had watched CCTV of Mr Paul in the hotel on the night of the crash walking around, laughing, joking and even tying his shoe laces with no apparent illness.

It was "very, very unlikely" Mr Paul had a 20.7% Carboxyhaemoglobin concentration, as found in post mortem tests, he concluded.

The court has heard how the tests found that Mr Paul, who was driving the Mercedes in which he, the Princess and her lover Dodi Fayed were killed, was almost three times the French drink-drive limit.

Richard Keen QC, for Mr Paul's family, claimed the blood samples tested for alcohol had not been checked against Mr Paul's DNA profile.

Prof Forrest qualified the claim, responding: "May never have been..."

But pressed again on the issue he replied: "I look to the jury (to decide) - conspiracy or cock-up?" The inquest continues.