Swimming legend Grant Hackett is reportedly being treated in hospital after he was released without charge from Southport police on Wednesday afternoon, following an altercation at his parents' Gold Coast home.
Police were called after the swimmer reportedly became abusive and aggressive and "flew into an uncontrollable rage" after excessive drinking, allegedly stabbing a knife into a chopping block before his arrest, news.com.au reports.
Addressing reporters following the incident, Hackett's brother Craig said that he was a danger to both himself and the community.
"This is not Grant Hackett. This is a completely different person. I don't know who this person is. My mum and dad don't know this person.
"He's there in person but he's not there in mind, soul or spirit... we know people struggle to get mental health treatment these days [and] we're no different to anyone else. We're struggling to get that help.
"We're pleading for people to help us -- help Grant. Grant needs help."
Hackett's father, Nev, who was at home with his wife when his son "broke down", told the Gold Coast Bulletin that the 36-year-old had been drinking heavily.
"He was raving and ranting a bit," he said.
"He's big and powerful when he's not happy... We decided he needed some treatment but there was no way he was going to go so we called the police.
"No one was touched. No property was damaged... He didn't even make any threats but was not what you say is a 'normal person'."
Hackett was filmed slumped down and handcuffed in the back of a police car as he was driven to Southport police watch house following the incident.
Following his release, the swimmer told reporters he was not feeling great and would be seeking help.
Last month, a court order was sought against the Olympian by one of Hackett's family members following an altercation that resulted in Hackett seeking treatment for a facial injury, the Bulletin reports.
The order, which expires in January 2019, requires that Hackett be of "good behaviour".
After his retirement following the 2008 Beijing Games, the three-time Olympic gold medallist has struggled with addiction and other personal issues.
In 2011 he trashed the Melbourne apartment he shared with his then wife Candice Alley and a few months later in 2012, was found asleep in a stairwell after being asked to leave a Channel 9 Logies party.
In April, following an incident on a domestic flight, the gold medallist issued an apology for "poor behaviour" following allegations he tweaked the nipples of another passenger.
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