A heart condition has forced the country's oldest cop to retire just short of a 50-year milestone.

Canterbury highway patrol Sergeant Clem Edmonds, 74, underwent a medical check in August after suffering vertigo while on deployment in Reefton. The results have ended his police career of 49 years.

"[The doctors] found it hard to address the situation and try and tell me 'Clem, maybe you should consider it's time to retire, get outside and enjoy your life without going through the stress of your job'."

Edmonds, who will retire in June, never really thought about joining police until his wife at the time handed him a police application form and told him to sign the dotted line.

The former railways worker is now the oldest serving police officer in New Zealand.

"I never expected to be in this career so late in my life at all. To me, age is not a barrier as far as work goes. As long as health is good, you're happy and you're keeping yourself fit, the more mature you are the much more easier the job becomes."

During a three-year stint in the army he went to Malaya and was based in Terendak Camp in Malacca as part of the 28th Commonwealth Brigade. He also spent six months in the bush in Borneo.

In the late 90s, Edmonds joined the highway patrol team. He was nicknamed the "smiling assassin" by colleagues for the way he approached motorists.

He can still recall giving his first ticket to Lady Wright, the then Mayor of Dunedin's wife. His last ticket was in August while patrolling the alternate SH1.

Edmonds was at his happiest working with the public.

"Give me admin work and I will chuck it out the window. There were opportunities to climb the ladder but I was more focused on being out in the field."

As he prepares for his final days, Edmonds says he will miss the camaraderie the most.

"You then become a family member of police and I think of it from that perspective, I'm actually a family member of the organisation and I will miss them."

Canterbury road policing manager Inspector Al Stewart says Edmonds would be missed by his colleagues and should be proud of his service, both with police and the Defence Force.

"He leaves a legacy behind that will be hard to match. He is still enthusiastic about work, and remains the consummate professional in his dealings with the community and his workmates."

- Stuff/Sam Sherwood.