A small Rotorua creek just a stones throw away from where Howard Percy was shot 35 years ago is being combed as police hunt for the murder weapon.
The 65-year-old was shot twice, while working as a security guard at Rotorua bank, on Old Taupo Road Bank in 1976.
After a recent tip-off, police have begun trawling through a small canal which runs along Sunset Road and Pururu Street around 400 metres away from the scene of the shooting.
The search is seeing dive squad members and USAR members use metal detectors to check both the canal and its bank, for a .22 calibre gun.
Detective Inspector Tim Anderson says as long as it hasn't been removed, it should be detectable.
"Given our research, and it's been documented overseas that numbers of exhibits and firearms and other weapons have been located even up to 50 years after the incident."
Changes in the landscape and affects of flood are just two obstacles police will have to work through as they hunt for the gun.
Detective Anderson says they're covering all their bases.
"The streams changed a little bit, we're covering off both the river or the stream and the banks of it, we're being very thorough."