SYDNEY • A former surgeon was yesterday found guilty of murdering five members of a Chinese-Australian family in Sydney, including two children, in a gruesome case that shocked the country.

Robert Xie, 53, was charged with killing his Chinese-born wife's brother Norman Lin, 45, Lin's wife Lily, 43, their sons Henry, 12, and Terry, nine, and Lily's sister Irene, 39. Their bodies were found in their north-western Sydney home in July 2009.

The long-running case saw Xie - an ear, nose and throat surgeon in China before he moved to Australia in 2002 - face four murder trials.

Two were aborted, one ended in a hung jury and the most recent re- trial lasted six months.

Xie was found guilty by the majority of a New South Wales Supreme Court jury, and will be sentenced on Feb 10, a court official told Agence France-Presse.

"I did not murder the Lin family, I am innocent," Xie told the court after the verdict was announced, the Sydney Morning Herald reported.

The newspaper added that Kathy, his wife, sobbed, saying: "He's innocent."

Prosecutors said Xie was motivated to kill his wife's brother and his family because he was enraged by his perceived lowly status within the family. "These perceptions invoked intense emotions on his behalf, including anger and resentment, and (he) directed these emotions at Lin and his wife," Ms Tanya Smith was quoted as saying.

The Sydney Morning Herald said yesterday there was also an alleged illicit sexual motive, details of which could not be reported due to non-publication orders.

Prosecutors also suggested a financial incentive for the killings, saying Xie had gone to great lengths to gain control of his brother-in-law's assets. These included the family's news agency, their North Epping home, a unit at Merrylands and a commercial unit which had just been leased.

The victims were beaten almost beyond recognition, their bodies lying in pools of blood, some splattered on the wall, according to the newspaper.

Prosecutors said Xie was carrying a hammer-like weapon - "assembled for maximum effect to incapacitate and kill" - and used it to beat Mr Lin and his wife while they slept in their bedroom.

Xie then crept to a second bedroom and killed Mr Lin's sister. Terry and Henry were murdered, possibly because they had seen Xie and would have been able to identify him. One of the boys was hit 18 times.

"It's apparent from the blood splatter patterns - there was a furious struggle in that bedroom," Ms Smith said.

For unknown reasons, Xie then returned to the parents' bedroom and rearranged their bodies so that they were lying in a V-shape.

It was Xie and his wife who discovered the bodies and called police.

Xie's main alibi, supported by his wife, was that he was in bed asleep with her when the crimes occurred, but the prosecution suggested that he could have sedated his wife and left home in the early hours to commit the murders at the nearby Lin residence.

The killings sparked a mammoth investigation spanning Australia and China, and Xie was eventually charged in 2011 and has been in remand since then.