Former Guantanamo Bay detainee David Hicks has heckled Federal Attorney-General George Brandis at an awards ceremony in Sydney.

"Hey, my name is David Hicks!" he shouted, as Senator Brandis wrapped up his address at a human rights awards function on Wednesday evening.

"I was tortured for five-and-a-half years in Guantanamo Bay in the full knowledge of your party! What do you have to say?"

As Senator Brandis walked off the stage at the Museum of Contemporary Arts, Mr Hicks told reporters he was a "coward" for not answering his question.