Child Abuse and Sex Crimes Squad Commander Detective Superintendent John Kerlatec said Paroci was "a great man and an excellent detective, and will be sorely missed by the team".
"Professionally, Josh was a tireless worker; dedicated to investigating some of the most heinous crimes against children," Kerlatec 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."
Paroci's family have requested their privacy at this time.
New Zealand Police continue to make inquiries on behalf of the coroner, and with the assistance of Maritime NZ, which is conducting its own investigation into what happened.
A post-mortem was due to be held in Invercargill today.
Paroci was on a commercial whitewater rafting trip on the Shotover River with Challenge Rafting.
He died on the same stretch of Shotover River rapids where rafting guide Keith "Chief" Haare died due to a medical event just two months ago.
The raft overturned on the "Toilet" section of rapids about 3.45pm. Paroci was in the raft with five other Australians and a rafting guide. There were two other rafts on the trip, along with safety kayakers.
A statement from the company said he was being brought back from the far side of the river using a rescue rope after the raft flipped, but he lost his grip.
"He was swept through the next rapid where he was met by the safety kayaker, who helped him navigate the subsequent rapid before assisting him to the shore," the Challenge Rafting statement said.
"He became unresponsive, CPR was provided and a defibrillator utilised. The guest received further treatment from paramedics who arrived by helicopter just after 5pm but was unable to be resuscitated."
He was pronounced dead at the scene.