The NSW police detective was on a raft with five other Australian tourists when it overturned on the Shotover River, north of Queenstown, on Saturday.
He lost his grip as the raft was being towed to a bank, was swept through another rapid and could not be resuscitated on the shore, Tim Barker, the general manager of Totally Tourism, which owns Challenge Rafting said.
"We believe everything was done by the book and standard procedure. But the outcome was certainly something we did not expect," he told Radio NZ on Monday.
Police colleagues on Monday paid tribute to Detective Senior Constable Paroci, who joined the force in 2008 and most recently worked at the State Crime Command’s Child Abuse and Sex Crimes Squad.
“The hardest part of my job is when we lose one of our own and my thoughts are with Det Senior Constable Paroci's wife, who is also a police officer, family, friends and colleagues," Commissioner Mick Fuller said.
"Det 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."
Child Abuse and Sex Crimes Squad Commander, Detective Superintendent John Kerlatec, said the police officer was a great man and an excellent detective.
“Professionally, Josh was a tireless worker; dedicated to investigating some of the most heinous crimes against children,” he said.
“His passion was justice for victims. Not only was he a police officer, he was completing a law degree, which he intended to use to create better outcomes for young victims.
“Josh was inspirational, and everywhere he worked, he turned colleagues into mates; today, we mourn the loss of our good mate.”
The death comes two months after a guide died in the same part of the river during a medical event.
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漂泊132年,西澳发现最古老漂流瓶纸条