A man has been found guilty of murdering his estranged wife in her Phillip Island home, after a jury rejected a theory by defence lawyers that she took her own life in the minutes after he assaulted her.

Adrian Basham, 45, was on Thursday found guilty of murdering Samantha Fraser in the garage of her Cowes home on July 23, 2018, the day after she celebrated her 38th birthday with friends and family.

Basham’s lawyers urged a Supreme Court jury to find the former construction worker not guilty, submitting that although he entered his former partner’s home, lay in wait and then surprised and assaulted her, Fraser was alive when he left just after 12pm.

The jury deliberated for about a day and a half but ultimately rejected the defence argument that Fraser died by suicide, and found Basham criminally responsible for the pyschologist’s violent death.

Justice Lesley Taylor remanded him in custody for a pre-sentence hearing on September 19.

Fraser’s friend and colleague, Alice Bradley, said the verdict was a relief.

“I’m pleased it’s over and with the verdict. It means the family can move on and start to rebuild their lives, although it will never be the same. It’s been a long four years,” she said.

Another friend, Lija Matthews, said she and others had waited a long time for confirmation of Basham’s guilt.

“We knew the truth from the start and we have waited 1368 days for it to come out,” she said.

“There’s a sense of relief, but nothing will bring our beautiful Sam back.”

Matthews said Fraser was “absolutely terrified” of her estranged husband. Her death prompted her friends to start an organisation, Change for Sam, that supports victims of family violence.