Ray Martin hosts Holt special.

Ray Martin will present a Nine special that seeks to shed more light on the disappearance of former prime minister Harold Holt.

Who Killed Harold Holt? will screen at 9:35pm on Tuesday November 20 in place of Crime Investigation Australia.

Historic, private footage found in the home of his stepson was recently released donated as a gift to the National Archives in Canberra.

It depicts Holt on a fishing expedition with Pick a Box hosts Bob and Dolly Dyer in 1967, just months before his disappearance off the Mornington Peninsula. It also shows him on an official tour of South Korea and hosting the Seekers folk group in Canberra in 1966.

We are only weeks out from the 40th anniversary, wonder why Nine didn’t time it to coincide with the date in December? Ratings season?

Harold Holt’s life was one of social success and secret scandals – yet all this Australian Prime Minister is remembered for is the mysterious way he disappeared, 40 years ago this year.

In the premiere special Who Killed Harold Holt?, Ray Martin explores that fateful Sunday morning of December 17, 1967 when Holt went for a swim at Cheviot Beach near Portsea in Victoria and was never seen again.

More than 30 years after his disappearance, a coroner finally ruled it was an accident, but it didn’t stop the rumours – and with so many unanswered questions, the conspiracy theorists had a field day.

Why would Holt be so reckless to go for a swim in dangerous surf? Why was he alone? How could we lose a Prime Minister in a popular place like Portsea? And could his death have been suicide?

Harold Holt was the nation’s leader for just 22 months, but he presided over a time of significant change in Australia . He was responsible for introducing decimal currency, giving Aborigines the vote, and introducing child endowment payments. He also went “All the Way with LBJ” into Australia ’s most controversial war, Vietnam .

The story of Harold Holt, a lawyer-turned-politician who was 59 when he disappeared, is a story encompassing everything from espionage to infidelity. This is a puzzling, enigmatic tale – of sex, submarines, and suicide.

Featuring interviews with eyewitnesses and journalists who covered the disappearance, as well as Holt’s sons, this special also uses re-enactments in a bid to finally uncover the truth. It also takes viewers to the other side of the world to really get to the bottom of the incredible and fanciful submarine theory behind Harold Holt’s disappearance – that Holt was somehow abducted by a Chinese submarine waiting off the Portsea coast.

To perfectly set the tone for the era, the Harold Holt story is carried by the fabulous foot-tapping music of 1967 – The Beatles, The Monkees, The Beach Boys, The Seekers, and Bob Dylan.

Join Ray Martin in his quest to find out Who Killed Harold Holt? when this special premieres Tuesday, November 20 at 9.30pm on Channel Nine.