The Governor-General has declined an application from double murderer Scott Watson to be pardoned.
Watson was jailed in 1999 for the murder of Ben Smart and Olivia Hope, who were last seen boarding a yacht in the Marlborough Sounds in the early hours of 1 January 1998.
Following unsuccessful appeals to the Court of Appeal and the Privy Council claiming his innocence, Watson applied to the Governor-General to be pardoned.
Justice Minister Judith Collins said on Tuesday that, after thorough consideration of all the relevant material, she advised the current Governor-General, Sir Jerry Mateparae, that the application should be declined.
Ms Collins said the cost of the Crown's involvement in a pardon sought by Watson is likely to run into the hundreds of thousands of dollars.
Watson's father Chris Watson said another application could be sent to the Governor-General.
"Until we've talked to lawyers I can't say what we're really up to, but we won't be giving it up. We may have to wait for a more receptive political climate than what we've got at the moment."
Mr Watson said his son is pessimistic about the decision, but is not giving up. Judith Collins said there was nothing to prevent him applying for another pardon if he wished.
Gerald Hope, the father of Olivia Hope, said that Scott Watson should make an outright confession or say directly that he is not the killer.
Mr Hope said until Watson speaks directly about the deaths, the case will never really come to a close, and his offer still stands for Watson to communicate with him.