An Australian man who died during a rafting trip in New Zealand's South Island has been identified as 31-year-old Joshua Paroci of New South Wales.

A New South Wales police officer, Detective Senior Constable Paroci was reportedly with five other Australians on the raft, operated by Challenge Rafting, which overturned on rapids on the Shotover River, north of Queenstown.

Police colleagues have described him as well respected and an excellent detective who would be sorely missed.

In a statement, the rafting company said the raft overturned about 3:45pm on Saturday near the Toilet Rapids at Skippers Canyon.

The company said the rafters followed standard rescue procedures when they were pitched into the water.

Detective Senior Constable Paroci lost his grip on the rescue rope as the raft was being towed to a bank and he was swept through another rapid.

Attempts by paramedics to resuscitate him on the shore failed.

Another member of the same group was injured and received treatment at a New Zealand hospital.

Joshua Paroci was on a guided rafting trip on the Shotover River, similar to this one, when he died. ( Supplied: Challenge Rafting - file photo )

Queenstown Rafting general manager Luke Taylor said he and his staff were devastated by the incident.

"Our hearts go out to our guests and the families of those involved in this. Both our companies wish to offer the group our sincere condolences and ongoing support," Mr Taylor said.

In a statement, NSW Police said Detective Senior Constable Paroci joined the force in 2008 and was a member of the State Crime Command's Child Abuse and Sex Crimes Squad.

His wife is also a police officer.

"Detective Senior Constable Paroci was well respected by all those who knew him and the police family will rally around his loved ones during this difficult time," Commissioner Mick Fuller said.

Detective Superintendent John Kerlatec, the Commander of the Child Abuse and Sex Crimes Squad, said the 31-year-old was "a tireless worker, dedicated to investigating some of the most heinous crimes against children".

"His passion was justice for victims," he said, adding that the young detective was completing a law degree which he had hoped to use to further help young victims.

"Josh was inspirational and everywhere he worked he turned colleagues into mates; today we mourn the loss of our good mate."

Challenge Rafting operates trips on the Shotover River. ( Wiki Commons: Ben Robinson )

Police said Detective Senior Constable Paroci's family had asked for privacy at this time.

The rafting company voluntarily suspended operations until further notice, and Maritime New Zealand is investigating the incident.

New Zealand Police confirmed Detective Senior Constable Paroci's death in a statement and offered "their condolences to Mr Paroci's family and friends at this difficult time".

The Department of Foreign Affairs and Trade said it was providing consular assistance.