The unsuccessful appeal to London's Privy Council by double murderer John Barlow could be among the last New Zealand cases heard by the Commonwealth appeal court.
Only New Zealand court decisions made before January 1, 2004, when the Privy Council was replaced by a new Supreme Court, can be heard by the law lords.
The Privy Council has agreed to hear only 10 New Zealand appeals in the past 150 years.
Among them was last year's appeal by David Bain in which the Privy Council quashed his convictions for murdering five family members, paving the way for his retrial which ended last month.
He was found not guilty by a jury in the High Court at Christchurch.
In yesterday's ruling on Barlow, the law lords found that he was properly convicted by the jury for murdering Wellington father and son Eugene and Gene Thomas in 1994.
The circumstantial case against Mr Barlow was "overwhelming", they said.
Mark Lundy, convicted in 2002 of the murders of his wife Christine and daughter Amber, could yet take a case to the Privy Council.
His lawyer, Christopher Stevenson, told NZPA that Lundy would appeal his conviction, but the forum had yet to be decided.
Initially jailed for a minimum non-parole period of 17 years, Lundy's non-parole period was increased to 20 years in August 2002 after his first, unsuccessful appeal against his conviction.
The other case which could yet find its way to the Privy Council is that of Peter Ellis. He was convicted in 1993 of sexually molesting children at the Christchurch Civic Creche where he worked.
Last year, lawyer Judith Ablett-Kerr said she was working on a petition to take the case to the law lords but no announcement has been made.
