Bones, skin and hair samples, including those from murder victims, from a macabre back-room police museum collection are being laid to rest.

The New Zealand Police Museum at Porirua has revealed it had 37 sets of human remains in storage from a collection used for investigative training by the detectives of the 1920s and 1930s.

But while some will be returned to living descendants, most will remain unidentified and will be cremated.

ROBERT KITCHIN Bullet cartridges are among the case evidence retained by the police museum from the Lakey murders.

Although the sad ending of some of the people in the collection - like the tiny victims of a notorious Wellington "baby farmer" hanged for his crimes in the 1920s - are recorded, many of their actual identities remain unknown.

The evidence has been largely untouched since the last known acquisition of body parts in 1957. The museum's director Rowan Carroll believedit was unethical to keep the body parts any longer and is now at the end of a three-year repatriation project.

"Once they have been laid to rest it will be a very big relief for me, because I've felt that they haven't been shown the respect they should have been decades ago."

The collection comprises five identified adult murder victims, one identified adult accident victim, four infanticide victims, 20 aborted fetuses and seven unidentified adults, whose causes of death are unknown.

Little is known about the body parts' provenance, aside from those that came from medical suppliers. Carroll believed the remains were sourced from trial evidence and instead of being buried with the rest of their owner's body, were kept for police training.

Carroll found no living descendants for the three of the six identified victims. However, her detective work poring through birth, death and marriage databases, newspaper archives and other documents, means three other victims' remains were being returned to their largely unaware descendants. Those victims' identities are not being released while the repatriation is under way, she said.

The rest, whom police have never been able to identify have already been cremated. Police will soon publicly announce the dates of public ceremonies to inter the seven "John" and "Janes Does'" ashes in Wellington. Four infanticide victims' remains will be interred alongside 20 aborted fetuses in a mass grave at the children's cemetery at Makara.

Such a grisly collection of relics is unlikely to be replicated in today's museums without the consent of victims or their families - not only because there is "no appetite for it," Carroll said.

"It would not happen again. We now have legislation that governs it."

A MACABRE COLLECTION

The stories of some of the unfortunate souls whose human remains feature in the New Zealand Police Museum's collection have been untold for decades.

The Police Museum was used for teaching from 1908. Much of the collection comprises the remains of people killed in the 1930s. Detectives might have analysed their remains to understand the physical effects of violent crime at a time when the role of forensic pathology in criminal trials was a shadow of what it is today.

The "baby farmer's" victims

Daniel and Martha Cooper ran a women's "retreat" in the Wellington suburb of Newlands that was really a back-alley abortion and baby farming business. They offered money and a place to stay for women with unwanted pregnancies. But as detectives discovered in a grisly backyard find in 1922, at least four "adopted" babies met tragic ends. Cooper was charged with murdering them, including two he had fathered himself. He was hanged but his wife was acquitted. Two baby skeletons were stored at the museum.

Read more: The Newlands baby farmers

Flags mark where police found the remains of babies in Isabel "Annie" Aves' backyard.

Abortionist Isabel "Annie" Aves

Twenty foetal remains and two infants' skeletons - all kept by the museum - were found buried in Hastings abortionist Isabel "Annie" Aves' garden in 1936. Aves helped women with their "problems," as a New Zealand Herald report of the time put it. It was in the days before abortions were legal. According to Te Ara Encyclopaedia Aves was a fashionable figure, noted for considering men financially liable for unwanted pregnancies - she would send "IOU" notes for the abortion costs to the fellows responsible for impregnating her clients. After three hung juries Aves was acquitted in 1937 - but was shot dead in 1938 by an abortion client's boyfriend after the woman became ill.

Samuel Pender Lakey

Farmer William Bally slaughtered his Ruawaro, Waikato neighbour Christabel Lakey and hid her body in a duckpond in 1933. He killed her husband Samuel Pender Lakey too - then burned the man's body and smashed his belongings and hid them in a sheep dip in a bid to frame the dead man for his wife's murder. As An Encyclopaedia of New Zealand noted it was a neighbour noticing the couple's cows hadn't been milked that alerted police to the brutal slayings. Bayly was hanged. Carroll's research into Bayly's motive found he thought the Lakeys were smearing his reputation as they suspected his involvement in another killing he was never convicted for. Samuel's burned boned fragments and hair sample will be interred in Christobel's unmarked grave at Huntly Cemetery.

Edwin Norman Armstrong

When Edwin Norman Armstrong began to lose his mind, his eldest son Douglas Armstrong feared for his mother and younger brother's livelihood. He killed his father in a fight in 1938, and dismembered him in an attempt to conceal his crime. Until a suitcase containing his headless and limbless torso floated up to Picton Wharf, the Evening Post reported. Another suitcase containing his arms, legs and head floated ashore a week later. Douglas was convicted of manslaughter and his mother died while he was still imprisoned. His brother died unmarried and childless and Douglas' history stops there, Carroll said. "I cannot find a single note about him, at all, and he certainly isn't a registered death within New Zealand." The museum will return four of Armstrong's leg bones to his Karori gravesite.

Herbert Henry Knight

Herbert Knight went missing in 1922. His bludgeoned body was found buried on his Johnsonville farm. Former employee John Tuhi was hanged for the murder. The museum will return Knight's "tiny" skull to his unmarked Karori grave, Carroll said. "The bones in his cranium were very, very thin. It was important that police understood how something as simple as whacking someone on the head could result in death because of the physiology of his skull."

The John and Jane Does

Among the seven sets of human remains police have been unable to identify was the top of a skull. What police do know is that the bone fragment was found in a vat of zinc at the old Kia Ora galvanising works in the Wellington suburb of Newtown in 1905, Carroll said. "They investigated that really thoroughly but they could not work out whether it had come in with the zinc or whether it was in the vat." All remains have been cremated and will be interred together at Wellington's Makara Cemetery.