Democratic members of the Financial Services Committee of the US House of Representatives have called on the panel to investigate the hacking of credit- and debit-card data of millions of customers of retailer Target.

The request piggybacks on a similar move by Senate Democrats on Friday.

The massive breach during the holiday shopping season resulted in the theft of about 40 million credit and debit card records and 70 million other customer records.

Meanwhile, Target began a major public-relations effort on Monday to apologize to customers, but the retailer was vague in providing details about what it knew and when.