The killer, who cannot be named as he was a youth at the time of the crime, was granted parole on March 18, just days before the 20-year anniversary of his victim's death.

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Paul Colin "Joey" Jarman suffered "horrific injuries" when the then 17-year-old boy, and two older men, attacked him on March 23, 2000.

The killers told the 26-year-old Invermay man they were taking him to a "secret marijuana plantation".

Mr Jarman was hit with a pickaxe handle, and a shovel and stabbed in the chest about 16 times with a knife.

His body was found in bushland between Mt Direction and Pipers River, with three men later charged with his murder - Leigh James Butwell, 36, Michael Adam Thompson, 19, and the 17-year-old.

A trial into the murder revealed Thompson was interested in the victim's partner, and began a sexual relationship with her the night after he and the others killed Mr Jarman.

Justice Peter Underwood in his Comments on Passing Sentence in December 2000 said the men "so savagely attacked him that he must have died almost instantly from horrific injuries to his head and body".

Describing it as a "dreadful crime", Justice Underwood sentenced the teenager to 20 years in prison, with a non-parole period of 10 years and nine months.

"This was a chilling crime of brutal murder in the nature of a gang execution," Justice Underwood said.

Butwell and Thompson were handed 25 years, with a non-parole period of 16 years.

In other news:

Butwell was released from prison in 2016.

The youth offender became eligible for parole at the end of 2010, but did not appear before the board until March this year.

Despite "a lengthy internal offending history", the Parole Board reported the prisoner had not committed any internal offences since mid-2017.

"Although the applicant is currently housed in a maximum security, he has achieved a minimum-security rating," the Parole Board said in its decision.

"The applicant is highly institutionalised having spent whole of his adult life in prison and has been assessed as requiring intensive support to successfully re-integrate into the community.

"It is notable that the applicant's custodial sentence is due to expire in less than 12 months' time."

He will be on parole until March 2021.

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