Signaller McCarthy, 25, was killed yesterday in a bomb blast in Afghanistan while conducting vehicle patrols in an area believed to be occupied by the Taliban.

Three other Australian soldiers were also hurt.

Signaller McCarthy was born in New Zealand and served in the Perth-based SAS, but grew up on the Gold Coast, attending school at Ashmore's Trinity Lutheran College.

Deputy head Tim Kotzur said Sean was a "prominent student" who represented the college in sports such as rugby league and water polo.

He also served on the Student Representative Council during his final year of school in 2000.

"Sean is remembers as a reliable, trustworthy young man whose great sense of personal integrity and maturity was apparent to all who interacted with him," Mr Kotzur said.

"Staff recall Sean as being quick-witted and having a great sense of humour, while remaining courteous and considerate towards others."

The school community was deeply saddened by news of Sean's death, he said.

"Our thoughts and prayers are with his family, friends and members of his unit at this difficult time, as we reflect on the life and achievements of Sean McCarthy."

Signaller McCarthy, who joined the army in 2001, earned a commendation following an earlier tour of duty in Afghanistan, and was known as a well respected soldier among his army colleages, defence force chief Angus Houston said today.