A police dive squad has wound up its search for the night of a Rotorua waterway, where police believe a weapon used in the fatal shooting of a bank security guard more than 30 years ago may have been dumped.
Howard Percy, who worked at an ANZ bank in Rotorua, was shot twice when he tackled a robber on Guy Fawkes' Day in 1976.
The bank, on Old Taupo Road, was robbed in July the same year, during which Mr Percy and two tellers were tied up and about $13,000 in cash stolen.
An investigation into the death was conducted but no one was charged.
Earlier this week, Bay of Plenty police and members of Mr Percy's family appealed for more information relating to the shooting.
Detective Inspector Tim Anderson says police began searching the Mangakakahi Stream after a reliable source indicated a weapon, believed to be a sawn-off .22 rifle, was thrown into the stream after the robbery.
The search has focussed on a kilometre-long stretch of the stream and its banks between Sunset Road and Pururu Street. It will resume on Saturday.
"Given our research, and it's been documented overseas, ... numbers of exhibits and firearms and other weapons have been located even up to 50 years after an incident," Mr Anderson says.
Police have received between 20 and 30 phone calls after the public appeal for information. They still want to talk to anyone who may have more information.