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Martyn Williams accused of entering Perth gym owned by Kelly Martinovic with a sledgehammer

Aerobics Oz Style TV star is embroiled in alleged sledgehammer incident just weeks before her son, 18, was accused of stabbing a teenager to death in a botched drug deal

  • Fitness buff Martyn Williams allegedly entered Perth gym with a sledgehammer 
  • The gym is owned by former Aerobics Oz Style TV star Kelly Martinovic
  • Ms Martinovic’s son Jaden is accused of stabbing a boy in unconnected incident 

A gym owner and former aerobics TV star was dragged into an alleged incident just weeks before her son allegedly fatally stabbed another teenage boy to death. 

Personal trainer Martyn Joseph Williams, 48, was allegedly armed with a sledgehammer when he stormed into Shredded Health and Performance on August 5, the gym owned by ex-TV star Kelly Martinovic.

The alleged sledgehammer incident was just three weeks before her teenage son Jaden allegedly stabbed a young drug dealer in the heart over a botched sale. 

Ms Martinovic, who rose to fame as a star of Aerobics Oz Style in the 1990s, is understood to have tried to end a business partnership with Williams and was encouraging him to step down as the gym’s director when the alleged incident occurred, The West Australian reported. 

Williams faced Perth Magistrate’s Court on Wednesday charged with one count of carrying an article with intent to cause fear that someone will be injured or disabled – which he denies.

His lawyer told the court Williams did carry the sledgehammer into the gym but he did not intend to threaten anyone. 

Martyn William (pictured) allegedly stormed into Shredded Health and Performance gym in Perth with a sledgehammer to threaten people

The gym is run by former aerobics TV star Kelly Martinovic (pictured)

The gym is run by former aerobics TV star Kelly Martinovic (pictured)

Williams was tackled by two personal trainers, who were at the gym at the time, and the alleged incident was captured on the gym CCTV.

The fitness buff is listed as director of the business from 2009 until September 2022 on his LinkedIn page.

Ms Martinovic is now listed as the director. 

Williams is on bail with his trial penciled in for March next year. 

Ms Martinovic’s son Jaden Martinovic, 18, will also likely stand trial next year over an unconnected incident. 

In September, he was charged with murder after he allegedly stabbed another teenager in the heart in a botched drug deal. 

Prosecutors allege police have dashcam audio from Mr Martinovich’s car on the night of the alleged incident where a bag of sea salt was sold under the pretence it was the drug meth.

Mr Martinovich had allegedly arranged the drug deal with the victim on social media before driving to a car park near Bourke St along with two teen associates.

Ms Martinovic's son Jaden (pictured together) is accused of fatally stabbing a teenager is a botched drug deal

Ms Martinovic’s son Jaden (pictured together) is accused of fatally stabbing a teenager is a botched drug deal

Police prosecutors will allege after a short conversation the victim got in his car and drove away while his two associates were still inside.

Mr Martinovich allegedly then chased the car down, opened the driver’s door, and told the victim  ‘get out, I have a knife’ before he stabbed him.

His lawyers previously indicated in court a not guilty plea would be argued on the basis the victim was car-jacking him and there was a struggle for the knife.

He is expected to front a Supreme Court trial in 2023.


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