A coroner's findings have revealed that Shane Martin, the father of AFL superstar Dusty Martin, died of cardiovascular disease late last year with drugs and steroids in his system.

The 54-year-old died face down and alone after suffering a heart attack at his Mount Maunganui home on December 17, 2021.

Subsequent post mortem tests found that Martin had a 600g enlarged heart, around double the size of an average man's heart.

A toxicology report confirmed that he was on steroids at the time of his death, with an associate Scott Williams telling police he believed Martin was a user.

"There was evidence in the urine for the use of the steroids trenbolone and nandrolone," the coroner's findings read.

Dustin Martin with his father Shane Martin in New Zealand. Photo / news.com.au

"Trenbolone is used on livestock to promote muscle growth and appetite. Nandrolone are anabolic steroids."

An earlier toxicology report found that Martin was also on anti-depression and pain relief medication after amitriptyline and azathioprine were found at the scene on the kitchen counter.

"Toxicology results … confirmed amitriptyline in Mr Martin's blood. Amitriptyline is used to treat depression and pain.

"Nortriptyline, an active metabolite of amitriptyline as well as a prescription drug in its own right, was also confirmed in the blood.

"The approximate level of amitriptyline appeared to be consistent with normal use."

Martin suffered from Chrohn's disease and also experienced anxiety.

On the morning of his death, he had complained to a friend of a headache.

Later that day another friend took him shopping before they returned to his home about noon. This was the last time that he was seen alive.

When Williams arrived at the house about 1.30pm, he found Martin lying face down on the bedroom floor.

Williams called emergency services and performed CPR until they arrived.

The ambulance crew arrived a short time later and took over resuscitation efforts, but despite continuing them for 40 minutes Martin could not be revived.

Police were satisfied there were no suspicious or untoward circumstances involved in Martin's death and the coroner chose not to open an inquiry into it.

It was revealed in May that Martin was facing violent criminal charges at the time of his death after he allegedly attacked a woman.

Police alleged he punched a woman, who he had been in an "intermittent relationship" with, in the face, threw her around the bedroom, grabbed her by the neck and squeezed.

He had pleaded not guilty to charges of male assaults female, strangulation, burglary and illegal possession of steroids.

Martin was deported to New Zealand in 2016 on "good character" grounds, separating him from his son Dustin in the final stages of his life.

This was despite the senior Rebels bikie member having lived in Sydney for the majority of his adult life.

During his father's time abroad, Dustin blossomed into arguably the best player in the AFL as part of Richmond's premiership dynasty.

He won three flags with the Tigers in 2017, 2019 and 2020 and won the North Smith Medal as the best player on the ground in all of those games.

He also received the league's highest honour, the Brownlow Medal, in 2017.

Dustin often spoke of his love for his father while he was alive and expressed hope that he would be allowed back into Australia one day.

"It's been a massive challenge, but it is what it is," Dustin told Fox Footy in March 2021.

"I love my dad and he's made me the man I am today.

"I've got full belief he'll (be) back here to watch us win another flag.

"That's my dream to be able to have the old man up there with the rest of my family and watch the Tigers win another flag."

Dustin took an indefinite leave from the game earlier this year in March to deal with the death of his father.

He returned to the club in late April but is sidelined with a hamstring injury as Richmond continues its finals push.

He has been continually linked with a move to Sydney throughout the season, with coach Damian Hardwick earlier saying Dustin has his "blessing" if he does seek a trade.

- Hamish Spence, news.com.au