Police have named the American tourist who plunged into Lake Wakatipu with his tandem skydiving instructor and has not been found.
He was Tyler Nii, 27, from California.
The Police National Dive Squad will arrive in nearby Queenstown during the weekend to assess conditions, as well as the viability of using sonar equipment to find Mr Nii's body, believed to be in a 250m deep section of the lake near Jack's Point.
The accident happened on Wednesday afternoon.
The instructor was plucked from the icy lake after about 20 minutes in the water and released from hospital on Wednesday night.
Inspector Olaf Jensen earlier on Friday confirmed the man was from the US.
Police say the search operation is very complex, given the depth of the lake.
A search on the surface was suspended after an extensive aerial operation failed to find Mr Nii.
The skydive company concerned, Queenstown-based NZONE Skydive, has expressed its sympathies and condolences to the missing man's family and friends.
It has suspended skydiving operations at the site and launched an internal review to assess its protocols but said it hadn't had a similar incident in 25 years of business.
According to NZONE, the instructor had completed more than 3000 jumps.
Police say members of the public witnessed the pair's fall and rushed to help.
"The self-tasking of those people contributed to the survival of the jumpmaster," Insp Jensen said.
"He was very lucky to be found."
The Transport Accident Investigation Commission has also begun a probe into the incident.
It earlier said the circumstances, as reported, indicated a possible parachute malfunction.