Police are calling for information from the public to help them solve the 1976 murder of Bay of Plenty man Howard Percy.

A team of investigators are continuing to comb through old evidence to try and identify Howard's killer.

Howard Percy was shot dead during a bank robbery in 1976.

The security guard was shot dead during a bank robbery 36-years-ago.

He had just purchased a farm in Bethlehem before he died.

Howard Percy, 65, was shot twice while attempting to stop an armed man during the robbery of the ANZ bank on Old Taupo Road in Rotorua in 1976.

The offender was never caught.

Police re-opened the case last month with hope new scientific methods will help locate the gunman.

Howard's son Ross Percy says he is pleased police have re-opened the case.

'It's great. The police have never given up on this case.

'It happened on Guy Fawkes so every Guy Fawkes it's brought to the surface again. It hurts.”

Ross had the following to say to the person who killed his father.

'Keep looking over your shoulder; the police are coming to get you.”

Ross says his father owned a successful engineering business in Hastings before selling up and moving to Bethlehem where he purchased a farm.

He was also a very active sportsman and took the security job because he 'was bored and wanted something to do”.

Howard worked as a security guard at the bank located in an industrial area on Old Taupo Road, which was open from 11.30am to 2pm Monday to Friday.

Three months prior to the fatal shooting, the bank was the subject of another armed robbery.

On July 16, 1976 an offender entered the bank and tied up two tellers and security guard Howard, who was on duty at the time, before stealing about $13,000 cash.

Then on November 5 shortly after the bank closed a staff member heard a noise at the rear of the building and when he went to investigate he was confronted by a man wearing a balaclava and carrying a sawn-off rifle.

Howard and the offender then became involved in a struggle and Howard was shot twice.

The offender fled empty-handed and Howard died on the way to hospital.

Police say an extensive investigation was carried out but no charges were ever laid.

Detective Inspector Tim Anderson says the passage of time doesn't lessen their resolve.

'In fact the passage of time can prove very useful as it allows us to make the most of advances in science and technology such as DNA and firearms analysis.”

A number of items were recovered from the crime scene including a knife and a blue woollen balaclava.

'We are in the process of having all of these items examined using means that weren't available 36-years-ago.

'We are also reviewing all of the original information to identify other possible avenues of enquiry.”

Tim says equally important is the public appeal.

'Not only does science and technology change over time; so do allegiances and relationships. It is possible that someone knew something crucial back in 1976 but their circumstances at that time prevented them from talking to us. Those circumstances may well have changed and we want to make clear it that the door is still open to them.”

A special phone line and an email address have been set up by police.

Anyone with information relevant to this investigation can call 0800 4PERCY (0800 473729) or email Operation.Percy@police.govt.nz

Alternatively information can be provided anonymously via Crimestoppers on 0800 555111.

Tim says Howard's wife died never knowing who murdered her husband.

'We want to at least give some answers to his children and his grandchildren.”