Grant Hackett arrested and in custody. Courtesy: 7 News Queensland

OLYMPIAN Grant Hackett allegedly “flew into an uncontrollable rage” that forced his parents to call the police to their Gold Coast home where he was arrested.

The swimming champion’s father Nev said the star had been drinking heavily and “had a mental breakdown” at the house in Mermaid Waters, the Gold Coast Bulletin reports.

Witnesses said 36-year-old Hackett was “going off” and stabbing a knife into a chopping block before the family reported a domestic violence incident, although no one was said to have been harmed.

Eight officers arrested the talented distance swimmer and he was taken to Southport watch house in a police car.

The troubled star hung his head low to the back seat of the car before raising his cuffs to a window and making the “shaka” sign, a friendly “hang loose” gesture associated with Hawaiian surf culture.

Hackett appeared dazed as he was driven away, dressed in a baseball cap, white T-shirt and shorts.

“Grant’s got a medical problem and it manifested itself here this morning … he was raving and ranting a bit,” his father told the Gold Coast Bulletin. “He’s been receiving treatment from a doctor. 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 and get treatment this morning so we called the police.

“The only way the police can do anything under the law of the land is to arrest him for domestic violence.”

Nev Hackett said his son “didn’t even make any threats but was not what you say is a normal person”, saying his doctor was likely to take him to Pindara Private Hospital when he is released.

The former Olympic champion is still in custody but is expected to be released later today without charge.

Queensland Police said in a statement they had arrested a man following a disturbance at an address in Mermaid Waters at around midday.

One of the greatest distance swimmers in history, Hackett is best known for winning the men’s 1500 metres freestyle at the Sydney Olympics in 2000 and at Athens in 2004, and captained the Australian swimming team for three years from 2005.

The 10-time world championship gold medallist has struggled in his personal life in recent years, after retiring from the sport in 2008, making a brief and unsuccessful comeback attempt in 2015.

In April last year, Hackett apologised after being accused of “forcefully” groping a passenger and “tweaking” his nipple on an interstate flight following a dispute over a seat being reclined too far.

Hackett phoned his alleged victim to apologise for his actions on the flight from Adelaide to Melbourne. He pledged to donate a sum of money to a charity of the man’s choice.

“I seriously and genuinely regret my poor behaviour,” he said in a statement. “I have stuffed up more than once and am working on these issues.”

It came a couple of years after the former Olympic hero spent time in a US rehab clinic where he was treated for a sleeping pill addiction after photos emerged of him looking lost with a singlet wrapped around his waist as a pair of shorts.

Before that there were two other high profile controversies. In 2011 he trashed the Melbourne apartment he shared with then wife Candice Alley, who was home with their twin sons.

Eight police cars were called to the luxury apartment after a distressed 000 was made to police.

Pictures emerged of the damage caused in the apartment — which included some of the items his wife most cherished like her piano, a dresser and framed photographs. A bedroom door was also destroyed, as were some of the children’s toys. The couple later said they were dealing with some “private issues”.

Months later, Hackett had an alcohol-fuelled night at Crown Casino during and after the Logie Awards in April 2012, where he was asked to leave a Channel 9 party and fell asleep in a stairwell.

At about 3am, the Olympian was approached by bouncers at a nightclub in the casino complex and told he should “call it a night”. Hackett is said to have fully co-operated with staff and left promptly without an escort.

The following morning, Channel 9’s Today aired footage of a sweaty Hackett at the party struggling to form a sentence. Asked by a reporter for his favourite song, Hackett stumbles: “I don’t know my favourite song ‘cos there’s are so many favourite songs. ‘Cos if I could name one I would.”

He and Alley split a month later and he was dumped from his ambassador role at the Alannah and Madeline Foundation which aims to protect children from violence.

More to come