Melbourne sinkhole forces closure of busy CBD street

A large sinkhole which forced the closure of a busy street in Melbourne's CBD was caused by a drainage crack, CCTV has found.

The hole, which is more than a metre wide and two metres deep, is on Collins Street in the heart of the city's CBD.

Engineers were on site assessing the hole, which runs over a water and gas main.

The City of Melbourne confirmed the cause of the sinkhole was a "crack in the barrel drain" running down the street.

"Crews are continuing an investigation into the road surface on Collins St after a sinkhole developed on the roadway this morning," the City of Melbourne posted on Twitter.

"Crews used CCTV drainage robot cameras to confirm the issue was caused by a crack in the barrel drain.

"We are currently repairing the road surface and drain and expect the road to re-open tomorrow."

This is not the first time Melbourne residents have woken to find a gaping sinkhole on their streets.

In January, a four-metre sinkhole opened next to a footpath in Keilor East, in Melbourne's north-west, following a powerful storm.

Traffic diversions remain in place for vehicles travelling eastbound on Collins Street, while crews repair the road.

The road will remain closed overnight.