The head of computing systems at US retail giant Target has quit her job in the aftermath of last year’s massive security breach.

Beth Jacob is the first senior executive to quit after the breach which cost the company $17 million (£10 million) after 70 million customers’ details were stolen in December.

"While we are still in the process of an ongoing investigation, we recognise that the information security environment is evolving rapidly," said Gregg Steinhafel, chief executive of Target. "To ensure that Target is well positioned following the data breach we suffered last year, we are undertaking an overhaul of our information security and compliance structure and practices at Target."

The company has issued a profit warning for 2014 and has said that it cannot estimate future expenses regarding the breach.