British Gas cyber attack leaks customer details online

The email addresses and passwords of 2,200 of its customers appeared online

British Gas sent an email to more than 2,000 customers on Wednesday evening to reassure them that the breach had not come from within the company (Getty)

British Gas has suffered a major security leak after the email addresses and passwords of 2,200 of its customers appeared online on Wednesday evening.

The company said in the aftermath that it was confident that the breach had not come from within the company. It also said no payment data had been compromised.

British Gas sent an email to more than 2,000 customers on Wednesday evening to reassure them that the breach had not come from within the company.

The email read: "I can assure you there has been no breach of our secure data storage systems, so none of your payment data, such as bank account or credit card details, have been at risk. As you'd expect, we encrypt and store this information securely.

"From our investigations, we are confident that the information which appeared online did not come from British Gas."

It was the third time in a week that a British company had suffered from a data breach. On Tuesday evening, the personal details of Marks & Spencer customers were posted online. A few days earlier, TalkTalk was targetted by a cyber attacker that leaked bank account details of customers online.

Additional reporting by PA.