The memorial at Catani Gardens in St Kilda was vandalised early on Wednesday morning.

Victoria Police officers and City of Port Phillip Mayor Marcus Pearl arrived to assess the damage just before 8am.

The statue has been targeted by protesters in recent years and was guarded by security last year.

In 2018 it was covered in pink paint as a protest on January 25.

Mr Pearl told 3AW radio on Wednesday the statue had not been vandalised since 2019.

"I'm disappointed, we had a very beautiful, respectful service with our traditional owners this morning and that was a fitting occasion I thought," he said.

"To come down and see this, certainly I was a bit disappointed but the rate payers are going to have to pay to get this cleaned up."

Mr Pearl said the council wanted to "focus on traditions that bring our community together, not tear us apart".

Several Invasion Day protest rallies have been planned in Victoria for Wednesday, including a virtual dawn service as the usual in-person march through the city was cancelled by organisers due to COVID-19.

Protesters will gather at Canberra's Aboriginal Tent Embassy - which marks 50 years of advocacy - before an expected march to Parliament House.

Australian Associated Press