Insurers have joined a class action that is seeking hundreds of millions of dollars for more than 4000 victims of the January 2011 Brisbane floods.

The action, filed in the NSW Supreme Court last week by Maurice Blackburn Lawyers, alleges Brisbane and Ipswich would not have flooded if engineers operating the Wivenhoe and Somerset dams had not repeatedly failed to ensure proper operations.

The claim, funded by Bentham IMF and filed against Seqwater, SunWater and the Queensland Government, alleges flood engineers made errors dating back to December 1 2010.

It says these led to huge volumes of water being released in January 2011 as a last resort to protect Wivenhoe Dam’s structural integrity.

Bentham IMF director John Walker told insuranceNEWS.com.au insurers and reinsurers have lodged about $100 million in claims under the class action, but he will not reveal which companies are involved.

He says the industry paid out more than $1 billion after the disaster, with reinsurers bearing the bulk of the loss.

“There has also been interest by insurers to join [the action] for claims in excess of a further $500 million,” Mr Walker said.

Bentham IMF will work with insurers over the next four months to accommodate those yet to join the action.

Swiss Re says it has not signed up, while a Munich Re spokesman told insuranceNEWS.com.au he cannot comment.

Suncorp says it is not a party to the class action “and does not have any financial interest in the outcome of any litigation. Reinsurers may consider seeking recovery of their losses. If they do, we will facilitate this and are prepared to provide them with materials relating to claims.”

A spokesman says Suncorp paid $686 million in claims and recovered $570 million from reinsurers.

Mr Walker says a hearing date for the action will probably be set in about 18 months.