A recent data breach of US retail giant Target's databases involved the theft of payment and personal details from up to 70 million customers, the company revealed today.
The figure is 30 million more than Target had first estimated and includes names, mailing addresses, phone numbers, email addresses and credit card numbers.
"I know that it is frustrating for our guests to learn that this information was taken and we are truly sorry they are having to endure this," said Gregg Steinhafel, Target's chairman, president and chief executive officer.
"I also want our guests to know that understanding and sharing the facts related to this incident is important to me and the entire Target team."
As part of the company's attempts to recompense its customers for the breach, Target is refunding the cost of any fraudulent charges arising from the data theft and offering one year of free credit monitoring and identity theft protection to all customers.
It is believed that thieves stole the data by installing code on to card-swipe machines at every single Target store in the US between 28 November and 15 December last year.
In 2013 it is estimated that 93 per cent of large organisations experienced a data breach. A study undertaken by the UK government's Department for Business, Innovation and Skills also revealed that 87 per cent of smaller businesses suffered from similar breaches.
On average large companies experienced 113 breaches last year, up almost 50 per cent on 2012 figures.