Martin Simpson, then a medical student and boyfriend of Gillespie’s daughter Vyner, says Holt and Gillespie enjoyed an easy, relaxed familiarity.

“Looking back … my abiding thought is that they worked well together,” says Simpson, a Balmain doctor and filmmaker.

“My lasting recollection is that they were in love. To see them together even briefly, the way they leaned into one another, they were obviously connected.”

He adds that Gillespie respected his memory in death, never speaking of him publicly, and withdrawing with a broken heart.

Gillespie, Vyner, Simpson and Alan Stewart, boyfriend of Gillespie’s deceased daughter Sheriden, were the only people on Cheviot Beach at midday on Sunday, December 17, 1967, when Holt tempted fate and rough seas to wade into the water.

Simpson met Vyner, an arts student, at Monash University.

On visits with her family, Simpson found Marjorie dignified, self-contained, and slightly melancholy as a result of Sheriden’s death in a car accident while travelling with Stewart, still a regular visitor.

“Marjorie was a beautiful, extremely elegant woman, with a bohemian touch,” Simpson says.

Simpson recalls meeting the Prime Minister early in 1967 at a cocktail party at the Gillespie home in Toorak, where Holt came into the kitchen for ice as Simpson chatted with Vyner.

“He stayed and chatted with us for a while and was very charming, a bit disappointing for a young leftie like me,” he says.

And while remembered for his obsequious “All the way with LBJ” pledge after a mid-1966 meeting with US President Lyndon Johnson, who became a firm friend, Simpson suspects Holt had regrets about the Vietnam War.

“Marjorie mentioned he felt very bad about the Vietnam War, after he made the commitment and all these young men started dying.”

The anointed successor of veteran Liberal PM Robert Menzies immediately dusted off the staid correctness of Menzies’ Canberra when he assumed the prime ministership in January 1966.

Menzies’ acolyte, former prime minister John Howard, noted Holt’s embrace of 1960s counter culture in The Menzies Era, recounting an early Holt meeting with prime ministerial press secretary Tony Eggleton.

Visiting Holt at a Canberra hotel, Eggleton recalled, “He greeted me at the door in his underpants. I knew things had really changed. Menzies would never have done that.”

Howard described Holt’s style as “open and sporting, always with an eye to … a photo opportunity. The three attractive women married to his stepsons garnered much publicity. A photo of them, bikini-clad, with their father-in-law in his wetsuit, became a signature image of the Holt era.”

Holt effectively ended the White Australia policy six weeks after taking office, while an election in November secured the largest ever parliamentary majority, winning 61 Liberal and 21 Country Party seats, leaving Arthur Calwell’s Labor Party with 41.

In 1967 Holt also successfully advocated for a referendum to include Aboriginal people in the Census, winning 90 per cent support for what began as a Menzies initiative.

Perhaps reflecting his “slightly bohemian tastes,” Holt favoured Australian arts by establishing a council for the arts and a national gallery. Art was likely an interest shared with Gillespie, a former art student who continued painting floral and still-life works into the 1970s.

Gillespie called Holt “Pablo”, says Simpson, a reference to the prime minister’s similarity to Picasso when posing for photos in his bathers.

The younger of goldminer and manufacturer Arthur Matear’s two daughters, Gillespie had enjoyed a privileged upbringing.

Her father’s family once owned the Australia Hotel in Collins St, Melbourne, and before her marriage Gillespie hosted cocktail parties with her sister Betty for up to 150 guests under a marquee in the garden of the family’s Toorak home.

In 1940, she married Winton Gillespie, then a shareholder in his family’s Society Entertainments business. They also had a son Wayne, later a Portsea architect.

Simpson recalls Winton spent most of his time cultivating commercial carnations at Portsea, while Marjorie favoured Toorak.

Holt and his wife Zara were neighbours after buying a renovated service building on one of eight lots when the Gillespies subdivided their Weeroona Ave property in 1961.

Simpson had told his mother he was spending the weekend with a mate when he headed out on a pre-Christmas visit to the Gillespies’ rambling sandstone home overlooking Portsea.

He recalls Holt calling at the Gillespies’ at 11am on Sunday. Marjorie left in Holt’s “big
old Yankee” Pontiac, while Stewart drove Simpson and Vyner.

Simpson says the pleasant day turned blustery, and Cheviot Beach was renowned for rock formations that created three gutters where water sucked back into turbulent holes just offshore but Holt often visited Cheviot alone to go crayfishing.

Simpson recalls feeling a strong undertow when he entered the water up to his knees. He left the water to go for a walk with Vyner.

“We weren’t gone for long,” he says. “When we got back Marjorie was standing on a rock in her bikini, with a chiffon-type beach dress blowing around her. She was shielding her eyes and looking out to the water, and we noticed a tear on her cheek.

“Vyner said, ‘Mum, what’s wrong?’ and Marjorie told us ‘he’s gone, he went out to the rock and he’s gone, like a leaf on the tide, he’s gone’. It took a while for me to comprehend what she meant, then my first thought was that my mother would find out I had lied.”

Simpson says by then the water looked ferocious, and Stewart was sent to get help at the quarantine station, which he felt then took “hours” to arrive.

“Marjorie was just incredibly quiet, she was so dignified,” Simpson recalls.

He is not surprised that Marjorie, who died aged 94 in 2013, or Vyner, who both moved to Mosman, never publicly discussed the events of that terrible Sunday.

Vyner, when approached at her Mosman home this week by Saturday Extra, still refused to talk about Holt’s disappearance.

“They are incredibly reserved and private, almost introverted,” Simpson says.

On future visits to the Gillespie home, Simpson says Marjorie remained warm and friendly, although “even more melancholy”.

A RESCUE DIVER REMEMBERS

Despite the turbulence, water around the rocks along Cheviot Beach remained clear enough to give rescue divers good visibility as they searched for missing Prime Minister Harold Holt.

“We had good visibility below the waves,” former Victoria Police search and rescue diver John Simon says.

“If he had been there, then I think we would have found him.”

Simon was on general duties in south Melbourne and on the reserve list for search and rescue when he volunteered to join the search mission.

“I remember I was watching Wide World Of Sport when there was a news flash,” he recalls. Simon was flown by helicopter to Portsea late on Sunday afternoon.

“It was decided it was too late and the sea was too rough,” he says.

The rescue team drove back to Melbourne, to fly back the next morning when three Iroquois helicopters ferried 38 police and navy clearance divers from Moorabbin.

“It was a big event, certainly the best resourced search I had seen, although the resources poured in back then are almost standard for most operations now,” Simons says.

On Monday morning, Simon says rescuers retained hope of finding Holt, or at least of recovering his body.

“I think there is always hope in the early stages,” he says, but acknowledged the open ocean beach was notorious for rips.

“It is not surprising that if you lose your footing on the sand, there is the potential to be dragged out.”

As divers searched rock ledges at the ends of the beach and rocks off the beach, extending out about 150m from the shore, Simon says water below the waves remained clear.

The search continued for three days, as helicopters flew along the coast.

“We would like to have found him. It would have been better for everyone.”