Tesco Bank has stopped its online operations for current account customers after reports that 40,000 accounts were hacked and money withdrawn from approximately 20,000.

In a message to customers this morning, chief executive of the bank, Benny Higgins, said: “Tesco Bank can confirm that, over the weekend, some of its customers’ current accounts have been subject to online criminal activity, in some cases resulting in money being withdrawn fraudulently. “We apologise for the worry and inconvenience that this has caused for customers, and can only stress that we are taking every step to protect our customers’ accounts. That is why, as a precautionary measure, we have taken the decision today to temporarily stop online transactions from current accounts.”

He added: “We continue to work with the authorities and regulators to address the fraud and will keep our customers informed through regular updates on our website, twitter and direct communication. We can reassure customers that any financial loss as a result of this activity will be resolved fully by Tesco Bank, and we are working to refund accounts that have been subject to fraud as soon as possible.” Shares in the supermarket slid 3% today on the news.