The state government has also conducted a review into energy regulator Energy Safe Victoria, which found “serious deficiencies” that jeopardized its ability to enforce bushfire reduction efforts.

Police said all four St Patrick’s Day fires were caused by electrical assets.

The 2017 Electricity Safety Performance Report said Powercor operated the largest network in Victoria. 

“The area it services is 82 per cent larger than AusNet Services and it owns 68 per cent more overhead lines than AusNet,” the report said.

“It is therefore not surprising that Powercor recorded the highest number of electrical safety incidents in the 2016/17 period. Even so, Powercor experienced 17 times as many pole failures and seven times more crossarm failures that AusNet services, despite only having 39 per cent more wooden poles.” 

Powercor is jointly owned by Hong Kong’s Cheung Kong Infrastructure and Spark Infrastructure.

Fairfax Media reported on March 11, six days before the St Patrick’s Day bushfires, faulty, damaged and aged electricity infrastructure had sparked more than 250 fires in two years, despite a key Black Saturday bushfires royal commission recommendation to minimise the risk.

The royal commission recommended giving the state's energy regulator ESV greater powers to reduce bushfire risk from electricity asset failure. But almost a decade on, that recommendation remains unfulfilled.

ESV data shows problems with electrical infrastructure such as power poles and wires caused 252 fires – or about 11 each month – between October 2015 and July 2017.

In January last year, the Andrews government commissioned a major review into strengthening the regulatory muscle of ESV. The review is complete but the public release of the findings has been delayed.

An interim report from the review, seen by Fairfax Media, found serious deficiencies with the regulator that have compromised its ability to monitor and enforce bushfire mitigation efforts.

Electrical Trades Union organiser Justin Sordello blasted ESV. 

“Sadly it seems that the weekend’s fires may be down to the lax regulator Energy Safe Victoria,” he said.

“Since the last bushfires royal commission, we have been vocal in our concerns that ESV is not doing its job of keeping Victoria’s poles and wires safe and functioning.

“We look forward to the important review the state government is doing and we’re confident that reforms to fix ESV will go a long way into reducing the risk of deadly bushfires in the future.

“Victoria needs whistle blower protections so that power workers can flag unsafe shortcuts before they turn into deadly mistakes. No worker should be punished for speaking up for safety.”

ESV said: “We have comprehensive compliance and audit procedures in place to ensure distribution companies implement and practice robust safety regimes”.

Environment Minister Lily D’Ambrosio said she had “sought an urgent update from ESV into the causes of the bushfires”.

“It is absolutely vital that the safety of Victorians is maintained - and I have asked Energy Safe Victoria to consider what additional action can be taken,” she said.