(CNN) -- After six and a half days of deliberation, an Australian jury convicted a surgeon dubbed "Doctor Death" in the deaths of three of his patients, Australia's national news agency said.
Indian-born Dr. Jayant Patel, 60, was found guilty of three counts of manslaughter and one count of grievous bodily harm in a Queensland Supreme Court, the Australian Associated Press said.
He had pleaded not guilty in the deaths of Mervyn Morris, Gerardus Kemps and James Phillips and in the bodily harm of Ian Vowles.
He entered the courtroom with his wife, Kishoree Patel, also a doctor. He stood with his head cast low and appeared calm as the verdicts were read out, AAP said.
Patel, who was extradited from the United States to stand trial, will be sentenced Thursday.
The verdict culminated 15 weeks of trial during which prosecutors told the jury about how Patel was an egotistical man who caused deaths and injuries by performing wrong operations, AAP said.
Prosecutors argued that Patel was criminally negligent in operating on the three men at Australia's Bundaberg Base Hospital, where he was director of surgery between 2003 and 2005.
The government made the case that Patel was a bad surgeon driven by ego and that he caused the deaths or injuries by performing the wrong operations on the wrong patients.
Victims' families told CNN Australian affiliate ABC news they felt vindicated.
Kemps' widow, Judy, listened to the verdict in court. She said she had not been sure if she would ever see the day when Patel was convicted.
"At one stage I thought it wouldn't. It's been a long five years, but it's all over," she told ABC.
Patel was licensed to practice medicine in New York state in 1980 and was fined and put on probation for "gross negligence and incompetence" in 1984, according to Australia's extradition complaint.
A few years after he was licensed in Oregon in 1989, his employer required him to obtain a second opinion for certain procedures, and state regulators prevented him from performing some kinds of surgery in 2000, the complaint stated.
Patel arrived in Bundaberg, sugar industry center, in early 2003.
The controversy over Patel in Australia mounted when concerns about his competency were voiced in Queensland's state legislature. A lawmaker had been tipped off by a senior Bundaberg nurse, ABC said.
Patel resigned and returned to Portland, Oregon. From there, he was extradited last year to Australia.