Police are not revealing what led them to charge a former lover of missing mother-of-three Sara Niethe with her murder.
Niethe and her car disappeared from the Hauraki plains in March 2003. She was 32.
Mark Pakenham, 49, appeared in North Shore District Court this morning charged with the Waikato woman's murder.
She was reported missing when she failed to return to her home in Kerepehi, north of Paeroa, after visiting Pakenham at his Kaihere property on SH27.
The last confirmed sighting of Niethe was at Ngatea on March 30, 2003 when CCTV footage recorded her making a purchase at a dairy.
Neither her body or her car have ever been found.
Pakenham was taken from Kawau Island yesterday afternoon, where he has been living recently, to Warkworth police station where he was interviewed and eventually arrested at around 6pm last night.
It marked the end of a new investigation by Waikato Police which begun after the original case was reviewed last year.
Police will not say what finally led to the arrest but admit key components of the case remain unsolved.
"We've neither recovered the body or the vehicle at this stage," Detective Senior Sergeant Mike Whitehead said
The case was re-examined in November last year and by mid-May a full investigation team was assembled, which led to Pakenham's arrest
"Time can be both an enemy and a friend with inquires, there are some benefits with time passing - people's allegiances and loyalties change, but there are obvious difficulties," Whitehead said.
Whitehead said the police had been in regular contact with Niethe's family, and he told her mother, Eileen Marbeck, of the arrest yesterday.
"They will be going through a mix of emotions at the moment, she expressed to me she was glad there was some progress but they are aware it is only the start to what will be a lengthy prosecution.
"As a family they haven't had the normal grieving processes we rely on to cope with loss like this and they still hold out hope that sometime in the future they will be able to give Sara a proper funeral."
Whitehead said hundreds of people had been interviewed for the investigation and written statements will now be considered by the Crown Solicitor.
He said they are not looking for anyone else in relation to the alleged murder and there is no indication where Niethe's body may be.