One of the country’s biggest private debt-collection firms was warned by regulators to “immediately cease” operating in Victoria just weeks before it struck deals to buy debt from major energy and telco companies, a Guardian Australia investigation has found.

Panthera Finance Pty Ltd, the nation’s biggest privately owned debt collector, is blacklisted from operating in Victoria due to a 2020 federal court ruling that it had unduly harassed three consumers for money they did not owe.