Hicks 'foolish but victim of injustice'

David Hicks was foolish to go to Afghanistan but has suffered injustice, Opposition Leader Bill Shorten says.

Mr Hicks' terrorism conviction has been overturned by a US military court at Guantanamo Bay, bringing an end to an almost decade-long legal saga.

His father Terry has called on the Australian government to apologise.

Mr Shorten said the government had questions to answer about Mr Hicks' treatment.

"There is no doubt on one hand David Hicks was probably foolish to get caught up in that Afghanistan conflict, but clearly there has been an injustice done to him," Mr Shorten told reporters in Melbourne on Thursday.

"I do think that the Australian government needs to examine did they really do all they could to ensure injustice didn't occur and bring David Hicks back to Australia."

He said while it was important to maintain national security, injustice should not be done to individuals.