Michael Rockefeller in the U.S before his disappearance.

New Guinea’s river-riddled southwest is the home of the Asmat people. Under the control of the Netherlands for many years, it was not until the 1950s that officials and missionaries finally made contact with the fierce Asmat, confirming that they practiced cannibalism as part of their spiritual and warrior culture. The waters of the Arafura Sea fringing their territory became known as ‘the cannibal coast.’

In the early 1960s, a young adventurer from the wealthy Rockefeller family came into contact with the Asmat during an anthropological filming expedition. Impressed with their culture and fascinated by their way of life, the 23 year-old Michael Rockefeller organised a return trip to study the Asmat more closely. Rockefeller was seeking adventure and also anxious to experience one of the world’s rapidly disappearing frontiers as well as documenting the customs and beliefs of an indigenous tribe.

The expedition began in October 1961. Michael and his companions followed a busy schedule of collecting and buying Asmat artefacts, trading for them fishing hooks and liens, cloth, tobacco and axes. He was particularly fascinated by the six meter carved wooden bisjpoles central to the spiritual practices and headhunting of the Asmat. The tall poles represented the ancestors and operated to ensure fertility of the soil and the continuation of human life.

A month later, Michael, together with a Dutch anthropologist named Rene Wassing and two local boys, was travelling in a motorised canoe through the Arafura Sea. Their intended destination was a wild area of southern Asmat country where the European presence was just one missionary. As they crossed the mouth of the Betsj River the canoe was swamped by a large wave. All four passengers were thrown into the wild water. The boys swam for the shore to summon help while Rockefeller and Wassing waited helplessly with the overturned boat, drifting further away from the coast. When it got light, Michael stripped to his underwear and tied two plastic jerry cans around his waist. With the extra buoyancy they would give him he began to swim towards the distant shore.

Unknown to Rockefeller and Wassing, the two boys had reached the town of Agats after many hours struggling through the swamps. They raised the alarm. A search plane spotted the capsized hull later that day and a rescue plane arrived the following morning. Wassing was saved but Michael Rockefeller was never seen again.

A desperate search followed. Did he drown from exhaustion and exposure? Perhaps he was taken by a shark or other predator? Or …? The Rockefeller family hired a Boeing jet and flew media to the area but they were unable to get closer than 240 kilometres to the coast where Michael was last seen. Official and unofficial efforts to find the missing millionaire were made and the event was reported around the world. But less than a week after his disappearance, the Netherlands government declared there was no hope of finding him alive.  A few weeks later the search was ended. But the mystery of Michael Rockefeller’s fate began to grow.

Michael Rockefeller was declared legally dead in 1964 but that did not stop the flow of speculations and dark rumours about the time, place and manner of his death. Or even if he was dead at all. One of the earliest elements of the legend had it that the missing adventurer was alive and living in the jungle, either of his own free will or perhaps as a captive.

In 1968 an Australian smuggler and gunrunner named ‘John Donahue’ claimed not only to have seen Michael Rockefeller but to have spoken with him. Donahue had been pursuing his nefarious business interests in the Trobriand Island group off northeastern New Guinea where he met a bearded and crippled white man being held captive by the Trobrianders. The man identified himself as Michael Rockefeller. He told Donahue that he had managed to swim to the coast from the drifting canoe, wandered through the swamps for several days, then broken both his legs in an accident. He was fortunately rescued – or captured – by a group of Trobrianders who were in the area on one of their regular extended sea journeys. They took him back to their home and were keeping him in their village. Why the Trobrianders wanted to hold this man was not specified. Donahue apparently disappeared before he could provide further details.

Little, if any, credible evidence exists for this throwback to the myths of castaway sailors forming colonies or integrating into local indigenous populations. And there are other stories.

Papuans on the Lorentz River in Western New Guinea during the third South-New-Guinea expedition of 1912-13. Tropenmuseum, part of the National Museum of World Cultures.

One popular explanation had it that the Netherlands authorities murdered a number of Asmat people in 1958. Asmat custom called for killings to be revenged and it is speculated that Michael Rockefeller did make it to the coast but swam into a revenge cycle initiated by the murders. The Asmat saw his sudden appearance as an opportunity to avenge themselves against the white men who had attacked them a few years before. In those days, Asmat revenge killings included taking the heads of their victims and eating their bodies.

More lurid versions of this explanation claim that the Rockefeller family hired private investigators to determine the fate of their son. One allegedly obtained three European skulls from the Asmat and, in return for a $250 000 fee, presented these to the family as evidence of Michael Rockefeller’s fate.

The Rockefeller family continues to mourn the loss of this naïve but passionate adventurer. In 2012 Michael’s twin sister published a memoir of her and her family’s struggle to deal with Michael’s disappearance. The enigma is still rehearsed from time to time in films, books, plays and the media.

Many of the Asmat artefacts collected by Michael Rockefeller, together with his photographs can be seen at the Metropolitan Museum of Art in New York and at The Peabody Museum at Yale University. While the man’s memory lingers on, so does his mystery.