Toutai Kefu is in a serious but stable condition in hospital after the Tonga coach and former Australia player was wounded during a burglary at his home.

Kefu and three members of his household were taken to hospital following an incident in the Coorparoo area of Brisbane that was reported to police at around 03:00 local time on Monday.

A man in his forties was confirmed to have suffered "serious injuries" after a violent altercation.

Two 15-year-old males have been arrested in relation to the incident, with Queensland Police confirming Kefu's wife, son and daughter were also receiving treatment for knife wounds at Brisbane's Princess Alexandra Hospital. A third alleged suspect is said to be unaccounted for.

"His initial condition was described as critical, but expected to survive," detective superintendent Tony Fleming told reporters on Monday.

"Mr Kefu is out of surgery and is stable now.

"His son is still receiving treatment as I understand and there's more treatment for Mrs Kefu and their daughter that will continue tomorrow.

"The mother has suffered very, very serious lacerations to her arm and I'm told her wounds are very significant."

Support for Kefu, who played 60 Tests for Australia, and his family poured in from across the world of rugby.

Superintendent Fleming stated that the family was awoken by noises in the house, with Kefu going to investigate.

"That person was accosted by at least one of the offenders in the premises and threatened to be stabbed if they didn’t hand over vehicle keys," Fleming said.

"Other members of the family came to that person's aid and during this time very significant injuries occurred to the family."

Kefu is Australia's most capped number eight of all time and helped the Wallabies win the 1999 World Cup. He coached Tonga at the 2019 tournament in Japan and was reappointed to the role earlier in 2021.

"Thoughts and prayers are with my Tongan brother Toutai Kefu and his family," former cross-code New Zealand star Sonny Bill Williams wrote on Twitter, while the Wallabies tweeted: "You got this great man!! All our love and thoughts to you and the entire Kefu family!"