Westpac is suing dozens of its insurers to recoup $400 million in policies the bank believes should have been paid out following the record penalty that was levied against it in 2020 for numerous anti-money laundering failures.

The local banking giant has lobbed legal action against Zurich-based Chubb in the NSW Supreme Court, but a source with knowledge of the situation told AFR Weekend that Westpac, overall, had proceedings under way involving 43 insurers including AXA, Allianz, Zurich and others.