No timeframe has been set down for when a retrial may begin in Mark Lundy's case, Crown Law says.
Lundy was convicted of murdering his wife Christine and daughter Amber in August 2000, and was sentenced to a jail term of at least 20 years.
Lundy's murder convictions were quashed by the Privy Council last night and he has been granted leave for a retrial.
"The court has said there should be a retrial, so as soon as a can be conveniently arranged, and the Crown process will be based on that advice,'' a spokeswoman for the solicitor general, Jan Fulstow, said.
The solicitor general and head of Crown Law, Mike Heron QC, does not need to make a separate decision to go to trial, but will follow the recommendation of the Privy Council that Lundy's case go before a jury, she said.
However, it is likely the next legal proceedings will be a bail application for Lundy.
A variety of issues will be examined before going to trial, including a review of the evidence and the availability of witnesses. The Crown will also spend time analysing the Privy Council decision and discussing it with police and the prosecution.
Prime Minister John Key said in Bali last night there was very little he could say about the case because it would be returning to the High Court.
He said he hadn't read the judgement.
Asked if it would be make a good case for compensation he said "That would be jumping to conclusions.''
First there would be a retrial and then an outcome of the retrial, he said.
"We'll take one step at a time.''
Asked if there was something wrong with the justice system given the quashing of convictions in the Lundy and Bain murder cases, Mr Key said: "There have been two very high-profile cases now where the Privy Council has essentially sent them back to the courts.
"Does that mean there's something wrong with our judicial system? No. It means that the final appellate court has decided that for whatever reason there is a case to go and re-look at the evidence that has been presented and the findings of the New Zealand Court.
"That happens to have been the Privy Council, but it doesn't mean it wouldn't have been the case if it had [gone] through the Supreme Court.''
"It just means these cases were in that system prior to the Supreme Court being in existence.''
Lundy's lawyer Malcolm Birdling has questioned whether the Crown will push for a retrial, saying it was not a given, TVNZ reported this morning.
Ms Fulstow said "there's a lot that can happen in any trial in terms of pre-trial matters'', but as it stands, there will be a second trial.
"The Crown is proceeding on the basis of the Privy Council, that the appellent should stand trial,'' she said.
In the decision - released at 9pm last night - the Privy Council unanimously decided that Lundy's appeal should be allowed; that the convictions should be quashed; that Lundy should stand trial again on the charges of murder as soon as possible; and until then, and subject to any High Court decision on bail, Mr Lundy should remain in custody.