It was 1966. 26th January to be precise. Australia welcomed a new Prime Minister into office - Harold Edward Holt. 

Harold was a bit of a controversial figure. He increased Australia's involvement in the Vietnam War by pledging allegiance to the then US President Lyndon Johnson. He was said to be a lady's man too. He did, however, also relax the White Australia policy, allowing non-Europeans to also come to Australia. He was liked and disliked for it. 

But his time in office is not why history remembers him. He spent all but 22 months in that position. The charismatic PM is sadly remembered for his tragic end.

Source: historicmysteries

His wife once said that Harold had a knack of getting involved with other women. One such person was supposedly his neighbour, Marjorie Gillespie. 

Down Under, it's summer even in December. So on 17th December, 1967, they planned a little outing. Marj with her daughter Vyner, Martin (Vyner's boyfriend) and a family friend, Alan, and of course, the Prime Minister, decided to go to the beach to watch a British yachtsman, Alec Rose.

Post that they went to Cheviot Beach, in Victoria, which had Holt's favourite snorkelling spot. While the rest of them resisted, Holt who was an accomplished swimmer, decided to dive in. The problem was that the tide was high.

Holt soon disappeared from view. The might of the Australian rescue forces descended upon the sea. But their attempts were futile. And just like that, Australia's 17th Premier was gone. Disappeared.

Source: heraldsun

Two days later, the government released an official statement, confirming the worst and an interim caretaker PM was sworn in.

Holt was said to be a very life approving person. But health wasn't on his side. Though his underwater prowess was much talked about, he was suffering from a recurring shoulder injury. Since he was on medication, he had been advised against swimming by his doctor.

Not just that, he had vitamin deficiencies due to which he had fainted in the Parliament earlier in the year and had almost drowned during snorkelling as well. But he refused the warning signs and the sea claimed his life.

Source: heraldsun

You have to understand that this wasn't just anyone who had drowned. Harold Holt was the sitting PM at that time. The country was shaken to its very foundation. And like it generally is with mysterious disappearances, a lot of conspiracy theories surfaced. Some ridiculous, some unbelievable. But all they did was complicate the entire issue.

Some claimed that he was Chinese spy since 1929 and a Chinese vessel had picked him up and taken him to Beijing. One said that he had escaped to Switzerland to stay with his lover. And one went as far as claiming that it was a CIA assassination. Apparently, Holt had planned to pull his troops out of Vietnam. Which seemed highly unlikely since he strongly endorsed USA's tactics.

Source: backoftheferry

According to Australian law, back then, no inquiry could he held by the coroner if a body wasn't retrieved. But a new law was introduced in 1985, which led to the case being reopened in 2003. 

Two years later, in September of 2005, based on his findings, the coroner announced that Holt had drowned due to the tide and bad weather. That put an end to all the conspiracy theories and the case of the Australian Prime Minister who vanished at sea.