A French anaesthesiologist is accused of killing nine patients while he allegedly triggered heart failure so he could heroically bring them back to life.

Dr Frederic Pechier has been linked to 24 suspicious incidents during his time at the clinic in Besancon, eastern France.

Pechier had his bail upheld on Wednesday at the Besancon court, despite prosecutors attempting to persuade the judge he should be remanded ahead of his trial.

Prosecutor Etienne Manteaux said Pechier was injecting lethal quantities of potassium chloride or anaesthetics and was 'omnipresent' in taking charge of resuscitation.

Frederic Pechier (right), suspected of poisoning and murder at the Besancon hospital, and his sister Julie Pechier arrive at the Besancon courthouse on Wednesday

Pechier outside the court on Wednesday where his bail was upheld despite prosecutors arguing he should be remanded in custody ahead of his trial

The 47-year-old denies the charges, conceding criminal acts were committed at the practice but not by him, NBC reported the prosecutor as saying.

The physician was arrested after nine patients went into cardiac arrest between 2008 and 2017.

Pechier was first charged in May 2017 and his trial has been delayed pending further investigations by the police who said they had broadened their inquiries to 'around 50 reports of unwanted events.'

Pechier's peers considered him a brilliant anaesthesiologist but his quick diagnostics for reanimating patients raised suspicions for investigators.

Pechier arrives at court with his sister on Wednesday, he denies all the charges against him

Prosecutors have alleged he was the only doctor present when traces of poison or overdoses were uncovered.

Pechier's lawyers have denied the claims, and in November they accused police of altering declarations he made during his initial questioning.

He has been forced to move away from Besancon, according to Le Fiagro, and is living with his parents outside Poitiers, where his father works in medicine.