In March 1996, 18-year-old Matthew De Gruchy bludgeoned his mother, younger brother, and sister to death at their Albion Park Rail home on the New South Wales south coast.

Key points: Matthew De Gruchy, who brutally killed his family in NSW in 1996, has been granted parole

Matthew De Gruchy, who brutally killed his family in NSW in 1996, has been granted parole Now 41, he has served 23 years of his maximum sentence of 28 years

Now 41, he has served 23 years of his maximum sentence of 28 years There are strict conditions around his release, but advocates say his family is concerned he will reoffend

The attack, carried out in a manner described by the sentencing judge as "seemingly frenzied", horrified the community.

The weapon was never formally identified, but is believed to have been a car jack handle.

De Gruchy was sentenced to a maximum 28 years in jail for the murders of his mother Jennifer, his 15-year-old brother Adrian and his 13-year-old sister Sarah.

After 23 years, the NSW Parole Authority formally decided to grant him parole in a hearing in Parramatta Court today.

Now, 41, De Gruchy was granted conditional release and was told he is not allowed to contact the family of his victims, except for his father, and that he cannot enter the Illawarra and Shoalhaven Local Government areas.

He will be released from prison in August.

The Albion Park Rail home where De Gruchy bludgeoned his family to death. ( ABC News )

A close to 'exemplary' prisoner

De Gruchy appeared via video link for the hearing and sat emotionless throughout the proceedings.

A court sketch of Matthew De Gruchy, who has been paroled after spending more than two decades behind bars. ( ABC News )

The Parole Authority found De Gruchy's behaviour in custody has been close to exemplary, with only two infringements of discipline in 23 years, he has also studied and obtained trade qualifications.

The NSW Government opposed parole because of the seriousness of the offences and the inappropriateness of his proposed accommodation.

But the Parole Authority found he had done everything demanded of him by Corrective Services and his future accommodation was suitable and satisfactory.

Outside the court, victim's advocates spoke on behalf of the family voicing concerns about his release.

De Gruchy family from left to right — Jennifer with baby Sarah, Adrian, Wayne and Matthew. ( Nine News )

'Should never be released': Family

Advocate Peter Rolfe said De Gruchy's uncle Ray Halliwell — the brother of Jennifer — was too distressed to speak publicly but he had talked to him on the phone after the hearing.

Mr Rolfe said Mr Halliwell was very disappointed.

"The family feel three lives were taken and De Gruchy should have been sentenced to three life terms and should never be released," Mr Rolfe said.

Advocates Peter Rolfe and Howard Brown say De Gruchy's family are concerned he will offend again. ( ABC Illawarra: Caitlin Dugan )

Mr Rolfe said Mr Halliwell also believed De Gruchy could do it again.

"He is of the opinion that De Gruchy will also be a danger to society," Mr Rolfe said.

"I just hope that he doesn't try to contact his uncle or aunt, or any members of the family."

The advocates said it was only because of a request from the family that De Gruchy would now be subject to a psychological assessment and support while on parole.

Advocate Howard Brown said the pain never went away for the family.

"No matter what sentence you give to the offender, we are the ones who get the life sentence," Mr Brown said.