He appealed for any sightings of a White 2007 Mitsubishi Outlander in the Manurewa area - the car that would later be found burnt out on the side of the road.
"Police are particularly interested in the vehicle's movements yesterday evening, or in the early hours of this morning across the wider Alfriston and Manurewa areas," Barry said.
A motorist discovered the grisly scene early this morning, before they pulled over and called emergency services, Barry said.
"The person that reported the vehicle on fire did find the car, the man immediately stopped and phoned Fire and Emergency. We are very grateful for that person for doing the right thing," he said.
CIB and forensic investigators have been at the scene today on Alfriston Rd today and were speaking to residents. A scene investigation was ongoing.
As a person has been arrested in relation to the investigation, Barry was unable to provide much more information apart from saying detectives were making "good progress" in the investigation.
"I would like to reassure the wider Alfriston and Manurewa communities that we have a team of detectives working diligently on the case," he said.
"Police believe this is an isolated incident."
A number of detectives wearing stab-proof vests were seen looking in and around the charred remains of the vehicle - the windows of which had been blown out, as had the roof.
Other offices clad in high-vis jackets stood guard within the cordon and not far from where a blue tent has been put up.
The vehicle had come off the road and into nearby bush.
Just behind it, on the middle of the road, were two bits of white-coloured material or possibly a shirt.
Police on Alfriston Rd, Manurewa, where a body was found in a burning vehicle. Photo / Dean Purcell
Victim's identity unknown
Authorities earlier said they were working with a man in relation to this matter and that he was helping officers with their inquiries.
Police earlier said its priority was to identify the person and find their next of kin.
Detective Inspector Chris Barry, of Counties Manukau Police, said fire crews attended the scene early this morning and extinguished the fire - before the body was discovered inside.
A large cordon is in place as officers continue a scene examination.
Alfriston Rd was closed between Mill Rd and Alfriston and motorists were told to find alternative routes or to expect delays, with diversions in place.
Local schools - including Alfriston (primary) School and The Gardens Early Childhood Education centre - remained open; but parents and caregivers were informed of the situation.
Those dropping off students at Alfriston School were told they needed to use the alternative Mill Rd carpark instead of the main entrance on Alfriston Rd.
Can you help? Anyone with information that may assist police is asked to contact Counties Manukau Police on 09 261 1321, or Crimestoppers anonymously on 0800 555 111.
