An examining judge in the eastern city of Besan?on placed Mr Péchier, 47, under investigation in May 2017 for the first seven poisonings. The doctor was later released but disbarred from practising medicine.
This week he was questioned by police about 66 cases of cardiac arrest during operations on patients who were considered low risk. The latest accusations are from these cases, involving patients aged four to 80.
Prosecutor Etienne Manteaux told local media that Mr Péchier had been "the common denominator" in each instance, and had been in open conflict with colleagues.
"He was most often found close to the operating theatre" when the cases occurred, said Mr Manteaux, and had made quick diagnosis on which action to take, "even when nothing allowed anyone to suspect an overdose of potassium or local anaesthesia".