About 900,000 Origin Energy customers affected by hack as company admits it was warned weeks before public told

Chief executive, Frank Calabria, apologises and advises customers to look out for suspicious activity amid heightened scam risk

Origin Energy has admitted it was warned of the hack that accessed 900,000 current and former customers' personal data three weeks before it first made the data breach public.

Australia's largest energy retailer said a significant" proportion of the 900,000 had been former customers, with those affected to be notified in the coming days.