The human remains found in suitcases bought as part of an auction for abandoned goods in a storage unit in South Auckland are two young children.

The Herald reported earlier today from several sources that the remains are two young children, which was later confirmed to reporters by Detective Inspector Tofilau Faamanuia Vaaelua.

He said the bodies - found at a Manurewa property on August 11 are two children - are primary school-aged, as ascertained by the post-mortem report.

Early indications are that the children could have been deceased for a number of years before being found, he told journalists this afternoon.

Police launched a homicide investigation after the remains of a body were found at a property in Moncrieff Ave in Clendon Park on August 11. Photo / Dean Purcell.

Vaaelua said he understands the discovery will be deeply upsetting for the community.

Police are still in the early stages of their investigation, he explained, but the children appear to have been dead for a number of years.

Police are following "positive lines of inquiry" in terms of the storage unit rental, Vaaelua said.

He said the children were aged between 5 and 10 and police were working on establishing when and where they died.

"What I can say is we are making very good progress with DNA inquiries."

They are looking at canvassing and collecting CCTV, Vaaelua said, but the number of years that had passed could make that challenging.

"We are doing our very best to conclude the inquiry and figure out what happened to these young children.

"This is no easy investigation."

Vaaelua said "horrific cases like this" are difficult for homicide investigators, especially those who were parents themselves.

He declined to answer several questions from media, saying the investigation may otherwise be compromised.

Relatives of the victims "were in New Zealand", he said, but police were also working with Interpol.

A neighbour on the scene at the time of the discovery told the Herald earlier this week there was "kids stuff in the back of the trailer: prams, toys, walker" which transported the suitcases.

According to police, people living at the Moncrieff Ave house brought "unowned property to their address" last Thursday and "are not involved in the incident".

It is understood the family purchased the contents of a storage locker as part of an online auction and found the remains in suitcases as part of the purchase.

A neighbour told the Herald the family found the remains in suitcases while they were unpacking and sorting through a trailer-load of the property on their front yard and driveway.

A man at the property on Moncrieff Ave, Manurewa, on Tuesday morning said he was looking after the house for his immediate family who had allegedly left Auckland after making the find.

"We're doing all right. As long as everyone leaves us alone we'll be all right," the family member said.

"They've gone away [the family who discovered the remains]. I wasn't here."

A police cordon was set up at the house during the weekend while forensic workers undertook a scene examination.

By early this week, police had left the address but large metal gates across the driveway were closed.

- Tom Dillane, NZ Herald