Convicted double murderer Mark Lundy has been granted a hearing in the country's highest court, but on very narrow grounds.
He has twice been convicted of murdering his wife Christine and daughter Amber in Palmerston North in August 2000.
He was first convicted in 2002.
In October 2013, the Privy Council granted him a retrial, but in 2015 he was again found guilty of their murders.
After being found guilty at his 2015 retrial, Lundy was returned to jail to resume serving his 20-year non-parole jail term.
His lawyers argued last week that the Court of Appeal was wrong to uphold the convictions.
The Supreme Court today granted leave for his appeal to be heard, but only on narrow grounds, limited to questions around the Court of Appeal's use of what's known as 'the proviso'.
That was the mechanism that allowed the Court of Appeal to dismiss Lundy's case, even though it found some of the scientific evidence put before the jury at his retrial was inadmissible.
He becomes eligible to seek parole in August 2022.