Billy Slater with wife Nicole at the Dally M's in 2011.

Billy Slater with wife Nicole at the Dally M’s in 2011. Photo: Marco Del Grande

Billy Slater’s wife Nicole has leapt to the defence of her husband saying the unprovoked night club fight could have killed the Kangaroos star.

The Australian fullback was detained by British police but was released without charge following an altercation at a nightclub in Manchester.

Slater’s wife Nicole posted a message on Instagram saying her husband could have died.

“Some man thought it was ok to punch my husband in the face because he thought he pushed in line,” Nicole wrote. “If he had king hit him and killed him I would have to raise my two kids alone.

“What has this world come to?”

A 40-year old man remains in custody after allegedly punching Slater outside popular nightspot Mojo Club – 10 minutes walk from the Australian team hotel – about 2.40am on Monday (1.40pm AEDT). Slater has returned to the team’s hotel.

“I have already lost a dad,” Nicole said. “Makes me sick. Think before you act, there is a family behind everyone.

“And your actions in that two seconds can change people’s lives forever. This has to stop.”

Teammate Josh Papalii was robbed by two men withdrawing £200 ($ 342) at an ATM, on Australia’s first night in Manchester three weeks ago.

The Australian team will remain in Manchester ahead of their clash against the USA in Wales on Saturday (Sunday, midnight AEDT). A victory there will see the Kangaroos relocate to London for their semi-final game.