A Perth prison inmate who tried to hire a hitman to murder his ex-wife for her life insurance money has been sentenced to more than six years in jail.

Key points: Gavin Napier met an undercover police officer to try to arrange the hit job

Gavin Napier met an undercover police officer to try to arrange the hit job The judge said the 45-year-old prisoner's motive "was purely financial"

The judge said the 45-year-old prisoner's motive "was purely financial" Napier will have to serve at least four years and four months in prison

Gavin Lloyd Napier, 45, was serving time in Hakea Prison in 2018 for possessing child exploitation material when he told another inmate he was "pissed off" with his former wife and wanted her "sorted" because she owed him $50,000.

Napier had been married to the woman for 12 years but they separated in 2012 after he came out as gay.

The Supreme Court was told the inmate said to Napier he "might know someone who can help", but instead he went to the police, who encouraged him to get more information.

The court heard in the weeks that followed, Napier told the man he could use his 2006-model car as a down payment, while the rest of the money would come from his wife's life insurance "once the job was done".

Police then arranged for Napier to receive a visit from a contract killer named "Billy" from the eastern states, who was actually an undercover officer.

Murder to be done 'any time, any way'

During the visit, which was secretly recorded, Napier provided his ex-wife's name, the suburb where she lived and the type of car she drove, saying he would also arrange for photos of her to be provided.

Napier arranged for the hitman to pick up photos of his ex-wife from his niece. ( Facebook: Gavin Napier )

The court heard Napier said "he wanted it to to look like an accident", he "wanted it done any time" and "any way", and he would "use his wife's life insurance to pay for the job".

He also requested that his wife's killer say to her before she died, "f*** you bitch".

The court heard he later said to the inmate he wanted it "to look like a clean accident so no questions would be asked".

The court was told Napier also tried to get his parents to transfer the ownership of his car to ''Billy", who it was arranged would pick up photos of the woman from his niece.

Motive 'purely financial', judge says

Napier pleaded guilty to a charge of attempting to procure the murder of another, with Justice Anthony Derrick saying the 45-year-old's motive was "purely financial" and borne out of the belief his ex-wife owned him money.

Napier will not be released from prison until 2024 at the earliest. ( Facebook: Gavin Napier )

He described the crime as persistent because it was committed over three months and said Napier had taken "a number of significant steps to bring about the death" of the woman.

He said an aggravating factor was Napier's involvement of his family members, who the court heard were still supportive of him.

Justice Derrick sentenced him to six years and four months behind bars, after taking into account that he was still serving an almost four-year jail term for the child exploitation material.

He will have to serve four years and four months in prison before he can be released on parole, meaning his earliest release date will be in 2024.