A communication breakdown between police and Child Youth and Family meant a teen was on the run for three months before crashing and dying in a stolen car.
Isaiah Elu Paora Nathan, 13, had been removed from his family and placed in foster care near Kaitaia in Northland but ran away in September 2010.
Sergeant Alison Holdaway from Kaitaia police told the Coroner's inquest at Auckland that she issued a missing persons report and followed it up with a message on a Child Youth and Family (CYF) social worker's phone.
Asked if she did anything else, Ms Holdaway said: "Unfortunately, I didn't do anything".
Police suspected Isaiah was returning to his family in Auckland where there had been complaints of domestic violence and neglect but Ms Holdaway said she did not believe the case was "serious".
Auckland-based Sergeant Marko Radojkovich said he had no record of communications from CYF on file.
Neither was there a record of Manukau police being notified by Northland police that the teenager could be in their area.
"We deal with hundreds of young people. If we thought he was in our area, we would have made enquiries."
Sergeant Radojkovich said Isaiah's case is one of many. Last year 54 children had run away while in CYF care. Police had 384 missing persons files for those 54 children, meaning some were likely to have run away up to 30 times.
Isaiah's social worker - who was given interim name suppression - told the court that he phoned family members to try to find the missing teenager and suspected family members were hiding him.
He was asked what formal contact he had with police.
"I didn't have contact with police."
He said there are no records of informal chats with police officers but "it is possible we talked about it".
He was asked by counsel assisting the coroner, Lily Nunweek, who was responsible for finding Isaiah.
"I would like to say we work together but it is very much the police responsibility. I guess we would have to work together."
A second social worker, also given interim name suppression, said he also could not recall "specific interactions" with police but said there were informal talks that were not recorded on the organisation's records.
At one point he was called to a family meeting and tried to get Isaiah to turn himself in but instead the teenager ran off.
The social worker said that information was not passed to police.
"We did not have a discussion with formal plans."
He said if he had specific information about where Isaiah was it would have been passed to police.
The social worker was asked what could be done to improve communication with police.
"I think we just need to ensure we are ticking some of the formal boxes rather than making assumptions about what the other one knows."
Isaiah was found dead about a month after the family meeting.
Police found his body in the driver's seat of a stolen Subaru Legacy. He had been doing up to 107km/h in a 50km/h zone and failed to take a corner.
The car went through a fence and two of the posts shattered the windscreen.
Four other teenagers aged between 12 and 15 were in the car. They ran from the scene and were later tracked down by police.
Sergeant Sascha Huff said toxicology reports showed traces of THC - the active chemical in cannabis - in Isaiah's bloodstream. He had smoked the equivalent of one joint in the six hours before his death but it was impossible to tell what effect it had on his driving.
There was also a trace of alcohol in his bloodstream.
She said by the time Isaiah was six years-old, his family had come to CYF attention because of neglect, emotional abuse, domestic violence and his alleged offending.
The inquest, before Coroner Katherine Grieg, is set to finish tomorrow.