Inquest hears missing schoolgirl's skull used as ashtray at pub

The man who found part of missing Mackay schoolgirl Marilyn Wallman's skull took it to a pub where it was used as an ashtray, an inquest has heard.

Greven Breadsell told police he had found the skull in 1974 at McGregor Creek near Mirani, about 40 kilometres from where Marilyn went missing two years earlier.

A 2015 video re-enactment of his discovery was played in a coronial investigation that is seeking to determine who is responsible for the 14-year-old's death.

During the re-enactment, Mr Breadsell said police questioned him about the skull in 1974 after he had taken it to a pub.

"I don't like to say this, but we took it over to the pub and used it as an ashtray one night," he said.

In the video played to the court, Mr Breadsell showed police where he saw the top part of a skull lying on grass in a cattle paddock, near an illegal dump site.

He told police he had gone to the property to collect palm fronds to shelter his mother's orchid house.

He said he initially thought what he found was an Aboriginal person's remains.

"Who else's skull would it be?" Mr Breadsell said.

"I had it at the shed there [at my home] for at least a fortnight or three weeks."

A pre-inquest hearing in August had heard that in 2006, updated DNA testing methods confirmed the skull was Marilyn's remains.

The court heard that in the past decade, Mr Breadsell had become close friends with person of interest Noel Morris, who was married to Marilyn's cousin at the time of her disappearance.

Marilyn 'scared' before disappearance

Trudy Voltz, a friend of Marilyn Wallman, told the inquest Marilyn looked "scared" the day before she disappeared.

Ms Voltz said Marilyn argued with another friend that day and had been quiet during a lunch break at North Mackay State High School.

The 68-year-old recalled that, at one stage, Marilyn had left to walk towards a school gate but did not say why.

Ms Voltz told the court Marilyn sat near a window looking out at the same entrance in maths class.

"I said to her, 'Who's out there?' And she answered me," she said.

"I think she said the word 'uncle.'"

The court heard Marilyn sat alone near the tuck shop after school and told Ms Voltz she did not want to catch the bus.

It also heard Ms Wallman declined to go home with her friend.

Earlier 'incident' with man after school

Council assisting the coroner, John Aberdeen, asked Ms Voltz to recall an "incident" on March 17, 1972, the Friday afternoon before Marilyn disappeared, involving Marilyn and a man.

Ms Voltz said she noticed her friend walking on the other side of the road outside the North Mackay State High School.

"A man approached her, and when she saw him, she took a couple of steps back," she said.

"He started talking to her … Marilyn had a very defensive pose."

Ms Voltz told the court the man was aged 19 to 20 and was about a "head height" taller than Marilyn.

She said she had assumed at the time it was someone Marilyn knew through her hockey club.

The inquest will continue Friday.