Grant Hackett in hiding after breakup with Gold Coast beauty Maggie Keating

Former Olympic swimming gold medallist Grant Hackett. Photo / Getty Images.

A messy end to his relationship with a beautiful law student is believed to have triggered troubled swimming champ Grant Hackett's latest emotional meltdown.

Hackett deleted photos of Gold Coast beauty Maggie Keating from his Instagram ­account just days before his highly publicised fight with his family, which led them to call the police.

After being released from the watch house, the three-time Olympic gold medallist then worried his family and his many fans by disappearing yesterday, sparking a desperate manhunt after his father Neville filed a missing persons report.

Hackett later called his ­father to let him know he was alive, but remained in hiding last night, amid ongoing fears about his mental health.

Ms Keating was unwilling to talk about the breakup of their six-month relationship, but she too has deleted all pictures of the swimmer from her social media accounts.

Hackett disappeared after he left the Palazzo Versace hotel on the Gold Coast yesterday morning without contacting his family and friends for more than seven hours.

His worried father Neville issued a public call for help in finding his son, saying: "He's mentally disturbed and needs urgent help. His doctor can't find him and he hasn't kept an appointment with his lawyer.

"When we spoke to him several hours ago, he just hung up when we asked him where he was. We're extremely worried about him."

Before disappearing, father-of-two Hackett took a swipe at his brother Craig, who had dubbed him "dangerous" to the media, claiming he "beat the shit" out of him.

Sharing an undated picture of him sporting an angry black eye to his Instagram account, Hackett wrote: "My brother comments to the media ... Does anyone know he beat the shit out of me? Everyone knows he is an angry man."

Hackett's brother said the family had cracked under the strain of dealing with the sporting hero's erratic behaviour and his parents were forced to call police, saying he had suffered a "mental breakdown".

"We've reached the end of the road," his brother said, after allegedly going to Hackett's house with their mother to stage an intervention. "He was in the middle of one of his benders," a friend said.

Friends say a lack of focus since Hackett's retirement and a succession of short-lived romances after his divorce from actress and singer Candice Alley in 2013 sparked an identity crisis and desperate search for purpose.

"He falls in and out of love easily," a friend said. "He needs a girlfriend and finds it difficult to be on his own."

The swimming great has struggled with personal issues and addiction for some time. He was involved in a drunken incident on a flight last year, and in 2014 he was filmed walking around The Crown Casino in his underwear claiming to be looking for his young son. That episode led to a five-week stint in rehab.