There can’t be many people who can say a rough day at work was worrying about a crazed gunman jumping from behind a bush and shooting you off your horse. That was how I felt on the trail of a crack-shot and would be assassin who wanted to shoot, stone dead, the Head of the Commonwealth Queen Elizabeth.

That white-knuckle ride through the wild, dense, bush of New Zealand’s West Coast , fording rivers and struggling up rocky hills, proved the genesis of a story that I bashed out on a rickety old typewriter. It won me an award and made world headlines for weeks.

We were looking for a 22-year-old armed robber called Christopher John Lewis who was on the run after knocking over a bank and post office. He claimed to be a Ninja warrior as well as a right-wing extremist and gun fanatic. In his first slip through police fingers he dived into a river to escape – apparently a Ninja-style way of evading capture.

My editors on the Dominion newspaper, in the capital Wellington, despatched me to the West Coast to report on the hunt. The photographer and I asked around and tracked down the four-man police sniper squad to a hotel bar and persuaded them to let us go with them on the manhunt the next morning.

So I came to grips with a horse – that I had no idea how to ride – from dawn, until dusk for a couple of days. Every half an hour, the police raised their telescopic sights, we dismounted and lay flat on the ground waiting for a bullet that, luckily, never came. I was 24-years-old and living every minute as if it were my last.

In the end, Lewis got away by hanging onto the floor of a passing train, before jumping on the ferry to Wellington and getting another train to Auckland at the other end of the country. Police arrested him – believe it or not – when he gave a credit reference to buy a car. A woman vouched for him and then tipped off police and Lewis, strangely enough, for a man of violence, went like a lamb.

Back in the bush my journalist antenna was working overtime. We had been led to believe Lewis was a mere felon; yet the police sniper squad talked of him as if he were Rambo and the Terminator rolled into one. I spoke to each of the snipers in their off guard moments in the bush to glean what I could – surprising how people will tell you stories face-to-face that they won’t do over email.

It led me, with the help of the news desk back, to retired Detective Tom Lewis (no relation) who spat out the whole story from his new home in Australia. He had arrested Lewis, back in 1981, and drawn him out by flattering his ego, telling him how he had given the police the run around, which led to the confession about attempting to blow the Queen’s head off as she walked the streets of Dunedin on the royal visit a few months before. Lewis had used the helpful map of the Queen’s route, published in the Otago Daily Times, to draw his field of fire and how many seconds he had to get in a head shot. His first shot was clear as day, the detective told me, from a roof overlooking the street. It was only a couple of policeman who climbed onto that roof, to get a better view of the Head of the Commonwealth, who messed up Lewis’s clear shot.

“There is no doubt he could have plugged her from there,” he told me. To this day, I wonder whether those policeman know their vantage point could have saved the Queen and averted a change in the course of history.

Detective Lewis recommended that the gunman be charged for treason that would have brought the whole story out. Police chiefs in Wellington were horrified – the revelation would have made them look like idiots and could have ended royal tours to New Zealand – and opted to sweep it under the carpet.

That is, until I came along six years later with my, dogged reporting, poor horse riding and rickety typewriting. It is immensely satisfying to see, 31 years later, in this age of fake news and sloppy reporting, that every word I wrote was verified by newly released intelligence documents; even more so, because the police at the time tried hard to pour cold water on my story.

If it had been possible to Google Christopher John Lewis in 1987 it would have been a lot easier and undoubtedly I would have got more information – but I probably wouldn’t have got the story.