After being found guilty of murdering his on-off girlfriend, James Hachem told a psychologist he grew up suffering abuse at the hands of his father and siblings.
The claims, which may play a part in determining the severity of Hachem's sentence, were scrutinised at a hearing in Sydney's Darlinghurst Supreme Court on Friday.
Hachem, 37, was found guilty last year of the murder of 30-year-old Samah Baker in January 2019.
He has always denied murdering Ms Baker, whose body has never been found.
Hachem said he was beaten severely by his father over a number of years growing up and would wear long sleeves to hide his wounds, according to a psychologist's report presented by the defence.
He also claimed to have been sexually abused by his grandmother and to have self-harmed from a young age by burning his hands with cigarettes.
Crown prosecutor Fiona Gray cast doubt on Hachem's version of events, saying the abuse did not appear in statements he gave to other mental health experts prior to his verdict.
She raised questions over whether such "ferocious beatings" and self-harm would have resulted in scarring.
Psychologist Kala Ram appeared as a witness, having conducted a mental status examination and psychometric testing on Hachem from prison via audio-visual link in November last year.
In her report, Dr Ram characterised the relationship between Hachem and Ms Baker as "casual".
"He said because it was a casual relationship, he wasn't bothered if she did date other guys," Dr Ram told the court.
Ms Gray presented text messages sent by Hachem to Ms Baker which she suggested painted a different picture.
One of the messages read, "I'm a piece of s*** because I can't sleep next to the woman I love because she's thinking about another man".
"Do you agree that suggests the relationship is not casual in the way that he characterised it to you?" Ms Gray asked.
"Yes," Dr Ram replied.
"Do you agree that he sounds angry and jealous?" Ms Gray said.
Dr Ram replied, "yes".
During the trial, the court was told Hachem and Ms Baker knew each other for about 15 years and, according to Ms Gray, were in an "intermittent intimate relationship".
Relatives reported Ms Baker missing on January 5 after a friend said she dropped her off at her Parramatta home in the early hours of the previous day.
The prosecution alleged Hachem was the last person to see her alive and the only rational explanation was that she was dead and he had killed her.
Defence barrister Daniel McMahon argued at the trial that suicide was one possible explanation for Ms Baker's disappearance.
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