A "seriously ill" man who murdered his part time girlfriend in 2013 has been released from jail to return to the town where he committed the crime to die.

David Jackson Mahia, 36, who is serving a life sentence for the murder and sexual violation of Invercargill mother-of-two Nicola Jean Fleming in 2013, was released from prison on September 17 to a family address in Invercargill.

In its decision granting his release, the New Zealand Parole Board said Mahia was "seriously ill and unlikely to recover".

Mahia was sentenced by Justice Cameron Mander to life in prison with a minimum non-parole period of 12-1/2 years for the murder, in the High Court at Invercargill in June 2014.

Mahia was also sentenced to a concurrent term of eight years in prison for sexually violating Fleming, during what Justice Mander said was a prolonged beating fuelled by Mahia's ''vengeful rage'', the Otago Daily Times reported.

In the attack outside an Invercargill hostel where Fleming was staying, Mahia left her so severely beaten she had a fractured face, pelvis and sternum, seven fractured ribs, and abrasions and bruising to almost every part of her body.

Mahia also had a serious criminal history with offending dating back to 1996, which included several instances of violence.

Mahia had applied for release from prison on compassionate grounds in July this year, but it was turned down by the New Zealand Parole Board, despite finding then he was seriously ill and unlikely to recover.

There were some "question marks" about the appropriateness of the address he wanted to be released to, and some concerns about "earlier intimidating behaviour by Mahia towards a corrections officer".

The board said it noted then Mahia was under good management in a purpose-built cell in the medical unit of the prison. There was also reference to a hospice placement at the appropriate time.

However, Mahia was firm he wanted to be released to an address provided by his family.

On September 13 the board considered a further referral from chairperson Sir Ron Young, who said seven weeks had passed since the last consideration, and he referred to updated information regarding Mahia's health.

The board also considered updated information about the proposed accommodation, where the Department of Corrections believed Mahia would be "manageable".

Mahia was released from prison on September 17 under special conditions that would remain for life.