The diary was kept by Andrew McIntyre throughout the 1960s and names his father Allan “Max” McIntyre, and family friend Anthony Alan Munro, in multiple entries.
Munro has been previously convicted on child sex abuse charges and is due to face sentencing in August for abusing boys in 1965.
Andrew McIntyre was one of his victims.
Fairfax reports that diary entries dating back to the days surrounding the disappearance of Jane, Arnna and Grant Beaumont say McIntyre was meant to go to the beach with his father and Munro that day, but was told to stay home at the last minute.
In a statutory declaration viewed by Fairfax reporters, Andrew McIntyre said he recalls his father and Munro being upset when they returned from the beach.
He reportedly claimed he saw blood and sand in Munro’s car.
McIntyre’s sister Ruth Collins corroborated the story and also made the extraordinary claim that she saw a child’s body in the back of the car.
Witnesses who were at Glenelg beach that day told police they had seen the children playing with a tall, blond man in his 30s, which fits the physical description of Munro at the time.
Police have previously interviewed Munro about the case, but found no evidence tying him to the Beaumonts.
The investigation is ongoing.
This article first published on Starts at 60.