In 1967, the disappearance of an American businessman in the hills of Cameron Highlands caused quite a stir in Malaysia and overseas. Not only was the victim a successful entrepreneur, the investigations bore no fruit and, to this day, no one knows what became of him.

Who was this man, and what could possibly have transpired?

Born in the US state of Delaware, James Harrison Wilson Thompson – better known as Jim Thompson – served his country’s military before starting a silk-weaving company in Thailand.

He proved to be a very successful businessman, with his company’s products being renowned for their quality. In fact, his efforts were said to have revitalised the faltering silk industry in Thailand, and his house in Bangkok remains a tourist destination to this day.

But there was more to him than met the eye – Thompson was actually involved in more cloak and dagger than one might imagine. You see, he was actually a member of the Office of Strategic Services (OSS).

It no longer exists today, but you might perhaps recognise its successor: the Central Intelligence Agency, or CIA.

What he did or saw during his service is anyone’s guess, but what is known is that in 1967, he came over to Malaysia from neighbouring Thailand for a holiday.

While visiting Cameron Highlands, he and three friends stayed at the Moonlight Cottage in Tanah Rata, which remains standing to this day.

On that fateful Sunday, they attended services at the nearby All Souls’ Church, after which the group returned to the bungalow to rest.

It was then that Thompson told his friends that he was going out on a walk. His companions expected him back within an hour or so, but he never came back.

A search was soon launched, with local police, volunteers, and sniffer dogs roped in. For 11 days they scoured the thick jungle, but there was simply no sign of the man, living or dead.

Unsurprisingly, given the mysterious circumstances around the situation, everyone and their grandmother began to develop theories on what had happened.

Numerous investigators have tried their luck at cracking the case, but as it stands, most of their theories are just that – theories.

Llewellyn Toulmin, a search-and-rescue expert, released an extensive report in 2015 detailing the disappearance and suggesting what could have transpired.

One theory he posited – but personally didn’t agree with – is that Thompson was eliminated by his own former employers.

A source alleged that Thompson had been sympathetic to the communists fighting the Vietnam War, leading to his assassination by the OSS.

But, according to Toulmin, there had been no indication that Thompson had ever been disloyal to the OSS, and he had served it well over the years. The Americans also lent a helicopter for the search and rescue, which they perhaps might not have done had he been a traitor.

Toulmin also rejects the idea that Thompson left the area in a car, as cars were rare sights in Cameron Highlands in those days, and the noise of an automobile would have been noticeable.

Another theory suggests that Thompson had been kidnapped by criminals who wanted a ransom for his release. However, the official police report makes this implausible: “None of these groups had knowledge pertinent to the victim’s disappearance,” it read.

If not bandits, maybe terrorists, then? The Emergency period had just begun and the jungles were infested with communist guerrillas.

Documentary-maker Barry Broman suggested this in his film “Who Killed Jim Thompson”. Purportedly, a friend had told him of an ex-insurgent’s deathbed confession that Thompson had been killed by guerrillas.

Is it plausible? Being a westerner with a history of espionage could have painted a target on Thompson’s back, after all.

Another theory suggests a lover’s tiff had ended Thompson’s life; the man had had quite a turbulent romantic life, with a short-lived marriage and rumours about his sexuality.

But although he’d had quite a few admirers and rivals, Toulmin asserts this does not provide sufficient evidence to support his disappearance.

The most boring but practical theory is that Thompson got lost in the jungle and had been eaten by a tiger. It’s not too far-fetched; the day before his disappearance, he had indeed been lost in the thickets with a friend, only reaching civilisation hours later.

Realistically, he could have been unable to find his way in the dense forest, and fallen into a ditch or ravine where few could find him.

Thompson was also not a young man at this point; he’d had several health conditions that easily could have weakened him, if not outright killed him.

But what of his remains? The jungle is thick and vast, so it’s not impossible the search parties could have missed him – perhaps they lay buried beneath layers and layers of mud. Who knows?

So, mystery solved then? Most definitely not. Like Amelia Earhart, this disappearance is unlikely to have concrete answers any time soon… if at all.

Still, if you want to have a crack at the case, head over to Cameron Highlands and walk the Jim Thompson Trail. Who knows what you’d find – a sightseeing tour where you can enjoy nature at its best… or perhaps a clue to this age-old mystery?