While it was still early days, Mr Lynch said he didn't believe roading had been a factor in the crash but it would be several weeks before inquiries were completed.
He said investigations were also continuing into the death of 29-year-old Stephanie McHale, who died after a two-vehicle crash on State Highway 5 near the Hemo Gorge Rd and Old Taupo Rd intersection last Wednesday.
A man in his 40s from the other vehicle remains in a stable condition in Rotorua Hospital. A second man was discharged last week.
He said there was a lot of background work police were doing around the crash.
Mr Lynch said the crashes, while "both tragic in their own right", didn't appear to be caused by common factors.
"Every journey on the road needs to be treated with care and caution."
FATAL CRASHES IN ROTORUA DISTRICT 2015:
October 18: A woman dies in a crash on Dansey Rd.
October 14: Stephanie McHale dies in a crash on State Highway 5 near the Hemo Gorge Rd / Old Taupo Rd intersection.
July 28: Blair Amundsen, 35, of Kinleith, dies in a crash on State Highway 30 near Horohoro.
April 25: Elisha Areli, 21, dies in a crash on Iri Irikapua Parade, Owhata.