A Captain Cook memorial in Melbourne's St Kilda was subjected to vandalism just hours before Australia Day, as culprits toppled and defaced the statue in an act of defiance.

The historic monument, located in Catani Gardens, St Kilda, was forcibly removed from its stone base around 3:30am on Thursday.

The vandals left behind a message, spray-painting 'the colony will fall' in red on the memorial base, while the statue lay hacked off at its ankles on the ground.

Liberal MP Angus Taylor expressed his dismay on the Today show, condemning the act and highlighting Captain Cook's historical significance.

Taylor questioned the motive behind vandalizing "a man of the enlightenment" and urged universal condemnation of such acts.

Port Phillip councillor Marcus Pearl denounced the incident as part of a recurring pattern of disrespect, particularly noticeable around Australia Day in recent years.

The statue, a frequent target for agenda-driven vandals, suffered similar incidents in 2022, 2020, and 2018.

As authorities launch an investigation to apprehend the vandals, concerns about the timing of the incident, just before Australia Day, underscore the ongoing debates surrounding the commemoration of the historical figure, fueled by a new wave of anti-European sentiment.

In recent years, activists have rebranded Australia Day as 'Invasion Day' marked by scheduled protests across major cities on Friday.

The public holiday commemorates the arrival of Arthur Philip and the First Fleet on January 26, 1788.