A "death squad" belonging to a white supremacist group has been accused of bludgeoning a man to death so that her de-facto partner could gain access to his life insurance.

Western Australia's Supreme Court was told Alan Taylor was murdered at his Girrawheen home, in Perth's northern suburbs, in April 2016.

Robert Wayne Edhouse and Corey Joshua Dymock, aged 22 and 21 respectively, and 36-year-old Melony Jane Atwood reportedly battered the victim repeatedly with a hammer has he lay on his bed in the home he owned, shortly after returning home from a shift on a mine site.

According to ABC News, prosecutor Justin Whalley said all three accused were members of the Aryan Nations. The group, Whalley added, claimed to strive for "equality in Australia, but in reality was just an affiliation of like-minded racists and white supremacists with an affinity for Hitler Nazism and the Third Reich".

Edhouse was the president of the group, while Atwood ran "a division" within the organisation called Aryan Girls.

The former also lived at Taylor's house in Girrawheen and was involved in a romantic relationship with the latter, the victim's de-facto partner, the court heard.

It is not yet clear whether Taylor was aware of the relationship but the prosecution said Atwood and Edhouse acted as "the driving force" behind the crime.

The prosecution stated that the trio, along with a fourth unidentified male, committed the murder before heading to the cinema to watch a movie in a what was described as a "futile" attempt to create an alibi for themselves.

"Forty-two minutes is all it took from the time this death squad arrived at the house until time they left [...] to execute their plan to kill Alan Taylor," the prosecutor said.

Following the murder, the three accused, which have pleaded not guilty, laughed about their actions, while Atwood boasted about the amount of money she would receive from her partner's life insurance.

"Killing him was her only option to maintain her lifestyle," the prosecutor added, explaining Taylor was the 36-year-old's only source of income.

Lisa Boston, Edhouse's lawyer, urged the jury to resist the temptation of allowing their personal views over the Aryan Nations into the trial.

"Acknowledge it and put it aside," she said.

White supremacist at a rally earlier this year.
A white supremacist at a rally in 2017 (file photo). Reuters