Flag burning at memorial 'reprehensible'

The burning of an Australian flag at the Anzac War Memorial in Sydney's Hyde Park is reprehensible and criminal, the NSW government says.

Police are searching for a woman seen there on Wednesday, when the flag was removed from the memorial and burned in its flame of remembrance.

Minister for Veterans Affairs Victor Dominello and RSL NSW President Don Rowe have condemned the incident.

"Not only is this criminal behaviour, it's deeply disrespectful of the memorial and all it represents," Mr Dominello said in a statement.

"It is deeply concerning that any person would seek to desecrate the Australian flag.

"Doing so on this sacred site makes it all the more reprehensible."

Mr Rowe urged members of the public to come forward with information.

"Veterans and their families will be outraged by this attack on a sacred monument dedicated to thousands of Australians who have fought and died for their country," he said.

Superintendent Mark Walton told reporters the flag burning was clearly not an accident but that investigators were still unsure why the woman did it.

Police will release CCTV footage of the incident later on Wednesday.

Police say the woman seen in CCTV footage is caucasian, aged between 35 and 45 and had light shoulder length hair.

She was wearing a black and white dress with black long sleeves and ballet flats.