SYDNEY -- An American doctor accused of botching a string of operations while he was the chief surgeon at an Australian hospital was found guilty Tuesday of killing three of his patients and grievously harming another.

Jayant Patel, 60, was ordered into police custody until he is sentenced on Thursday after a jury returned guilty verdicts on all charges against him.

Patel, 60, had pleaded innocent to three counts of manslaughter and one count of causing grievous bodily harm to four patients he treated while working as director of surgery between 2003 and 2005 at a state-run hospital in Queensland state.

He faces a maximum penalty of life in prison.

The trial came more than 25 years after questions were first raised about Patel's competency, and marks a milestone for many former patients who have waited years to face the man they accuse of irreparably damaging their lives.

The trial heard that Patel had been banned by U.S. authorities from carrying out some of the procedures he undertook when he later moved to Australia. He had failed to inform his new employers about the restrictions.

At the trial, prosecutor Ross Martin described Patel as a "bad surgeon motivated by ego" who tried to restore his reputation by carrying out surgery he was not competent to perform.

Patel did not speak at the trial, but his defense lawyer said he was a hardworking doctor devoted to his patients, and that all of the patients named in the case had consented to the surgeries and knew the risks.