Kowalski, the Australian Swimmers' Association boss, battled Hackett in the pool and has remained in touch with the 36-year-old through his struggles.

But after the three-time Olympic gold medallist's arrest on Wednesday, Kowalski says the time has come for Hackett to face his demons.

"He's been very good at hiding he's got issues, other than when these instances have exploded," Kowalski told SEN radio on Thursday.

"That's my biggest concern, that he's lived with this for so long and he's covered it up for so long.

"When yesterday happened, I must admit I wasn't totally surprised because it was more a matter of 'when' not 'if'.

"(He needs) some tough love and (to) go to a place that won't let him check out of rehab early.

"Hopefully he can look in the mirror now and say, 'right, it’s now or never'.”

Hackett was taken to Southport Police Station on Wednesday after his parents phoned authorities due to his erratic behaviour.

It is the latest incident involving the former 1500m who has previously admitted to struggles with mental health and alcohol.  

"When it gets to Grant's situation, I just don't know what more the sport could have possibly done," Kowalski said.

"The resources and the money, we just don't have them. You rely on people talking and seeking help and advice and going to someone, but it's a really taboo subject still.