Death" Harold Shipman joined the ranks of the world's worst serial killers on Friday when an official inquiry ruled he had murdered at least 215 of his patients.

Dame Janet Smith, who headed the inquiry into the deaths of almost 500 Shipman patients, said he had murdered at least 200 patients by lethal injection over 23 years. Those deaths come on top of the 15 patients he had already been convicted of killing.

Smith said she also had "real cause" to suspect that the soft-spoken doctor might have killed another 45 while working as a trusted family doctor in Northern England and found it "deeply disturbing" that he did not arouse suspicion for so many years.

"Deeply shocking though it is, the bare statement that Shipman has killed over 200 patients does not fully reflect the enormity of his crimes. As a general practitioner, Shipman was trusted implicitly by his patients and their families. He betrayed their trust in a way and to an extent I believe is unparalleled in history," Reuters quoted Smith as saying in her report.

The killing spree ran from 1975 to 1998: 171 victims were women and 44 were men. They ranged from a 93-year-old woman to a 41-year-old man.

The findings confirm the family doctor as one of recent history's most prolific serial killers, on a par with Colombian Pedro Lopez -- dubbed the "Monster of the Andes" -- who was convicted of 57 murders in 1980 but is suspected of killing 300 young girls.

Shipman was jailed for life in 2000 for murdering 15 mostly elderly women patients by lethal injections of diamorphine, the clinical name for heroin.

The report found he remained faithful to his preferred, bloodless method of killing throughout. Smith said the typical killing involved a home visit to an elderly patient.

"During the visit he would kill the patient.

Afterwards he behaved in a variety of ways and had a variety of explanations for what had happened," Smith said. "The way in which Shipman could kill, face the relatives and walk away unsuspected would be dismissed as fanciful if described in a work of fiction."

Shipman is to be sent a copy of the vast report in Frankland jail, county Durham, where he is serving life.

---- Devastating News ---- Relatives of the dead were informed of the inquiry's findings on Wednesday, giving them 48 hours to come to terms with the news ahead of the public release of the report.

"So many people are so upset, shattered by their news that their mother or father or granny did not die the peaceful death they believed but was actually murdered," said Father Denis Maher from St. Paul's Catholic Church in the small town of Hyde where most of the victims lived.

The killings began with a Mrs. Eva Lyons from Todmorden in 1975 and ended with Kathleen Grundy from Hyde in 1998. It was her death that finally led to Shipman's arrest after he forged her will in his favor.

Once highly respected, the bespectacled doctor has never admitted his guilt, leaving others to speculate on why.

Described as a caring, if arrogant, man, prosecutors at Shipman's trial said his drive to kill was fuelled by a desire for a God-like power over life and death.

Others speculated Shipman was influenced by watching his mother die from cancer while he was still a teenager.

Shipman's wife Primrose, whom he married when she was 17 and he was 20, has stood beside him ever since his arrest, refusing to accept his guilt. The couple have four grown children.

A greater Manchester police spokeswoman said Shipman would not be prosecuted for any further murders because of the virtual impossibility of finding a jury unaware of his previous history.