The cause of a bushfire that destroyed 193 houses in the Blue Mountains has yet to be determined, according to lawyers for a power company facing a $200 million class action.

Endeavour Energy has no view on the cause of the October 17 blaze because police have seized the relevant section of power line and blocked access to the site during their investigation, barrister Michael Izzo told the NSW Supreme Court.

An Endeavour spokesman told insuranceNEWS.com.au a coronial inquiry will start on July 11.

The Supreme Court heard 300 residents have registered for the class action, with another 100 likely to be involved.

Justice Peter Garling intends to set a hearing date for between July and December next year.

The matter is to return to court this July 30 after lawyers for the plaintiffs file an amended statement of claim and Endeavour responds.

The class action has been filed by Maddens Lawyers, which alleges the blaze at Springwood and Winmalee began after a “poorly maintained” tree – flagged as a hazard three months earlier – fell on power lines.

A hazard notice was issued to a Springwood property owner, asking him to trim the tree, but Maddens says state-owned Endeavour was obliged to ensure it was complied with.

Maddens estimates the claim will exceed $200 million for property loss and damage. Many of those who lost homes or suffered damage were underinsured or had no insurance.

The law firm has settled four similar class actions concerning the Black Saturday bushfires in Victoria in 2009.