Otago Museum Maori curator Rachel Wesley said the 165-year-old piupiu was given to Toitu Otago Settlers Museum about four months ago, by Jenny Morgan, the great-granddaughter of Ralph Nicholson who worked as a chemist in Dunedin in 1851, then moved to Tasmania in 1852, and returned to the city in 1863.
An analysis of the piupiu suggested it was made in the 1850s.
The exact origins of the harakeke flax waist garment were "unknown", but it was thought Mr Nicholson may have received it as a form of payment while working as a chemist in the city.
"It’s life history before it came into the Nicholson family is unknown ...
"It had been passed down through the family and stored in cupboards for a long time, type of thing."
The piupiu was originally given to Toitu Otago Settlers Museum about four months ago, but its degradation and history made it better suited to the Otago Museum piupiu collection, she said.
"It is a really nice addition to the collection of local piupiu and textiles that we have.
"To have one that has this provenience is really special."
Otago Museum conservator Lisa Yeats said while the garment was not in an "unsalvageable" condition, it was fragile.
The garment would initially be stored in a temperature and light-controlled room to prevent damage such as ultraviolet light degrading it further.
Some harakeke strands had become detached and would need to be fixed if it were to go on display, she said.
Ms Wesley said the museum was excited by the "significant" addition to its Maori garment collection.
"It’s not quite absolute Sunday best, but it is definitely not everyday wear.
"It is a very special addition."
It was not known when the garment might go on display.
