Protest slogans sprayed on Sydney statues

Monuments to Australia's colonial past have been vandalised in Sydney's CBD as the public fiercely debates changing their inscriptions.

Statues of James Cook, Lachlan Macquarie and Queen Victoria were among the targets of what police believe is a lone vandal, spotted walking through Martin Place on CCTV the night of the attacks.

The words "change the date" and "no pride in genocide" were spray-painted on the monuments.

The slogans allude to a growing public debate about the way the European arrival in Australia is commemorated.

Graffiti was also sprayed on the Archibald Memorial Fountain, ANZAC Memorial, several park benches in Hyde Park, and in Martin Place.

Police released CCTV images on Saturday that depict a man of Caucasian appearance with a beard and wearing black sunglasses, a khaki coloured jacket with a red shirt or scarf underneath, black track pants and brown boots.

The graffiti attack comes just days after indigenous broadcaster Stan Grant called for the inscription on the Cook statue - saying he "discovered" the territory in 1770 - be changed.

But Grant has described the attack as "appalling" and "vandalism".

Prime Minister Malcolm Turnbull dismissed changing the plaques as a "Stalinist exercise" in rewriting history.