Prank turns Carlton Gardens pond into crimson lake but richer hues won't last

The water in a fountain and nearby lake at Melbourne's Carlton Gardens have turned a deathly shade of red.

On Friday morning it was discovered that the iconic Hochgurtel Fountain in front of the Melbourne Exhibition Centre was spewing blood-coloured water.

A Melbourne City Council spokeswoman said the dyed water was "non-toxic" and therefore thought not to pose a danger to local plants and animals.

This is lucky for the ducks who, unperturbed by the change of scenery, were photographed paddling through the crimson lake.

"Remediation works are currently underway to drain the fountain and the lake," the spokeswoman said.

"They should both return to their normal colouring by tomorrow."

There has been speculation the prank could be the work of University of Melbourne students taking part in this weekend's Prosh Week celebrations.

The incident has been reported to Victoria Police.

The suspected prank harks back to startling photos that recently emerged of the Daldykan river in far north in Russia, transformed a dark shade of red.

The colour change there was later traced back to a spillage at a local metals plant.