"It appears that some mobile phone companies' call centres in India are being targeted by criminals intent on unlawfully obtaining UK citizens' financial records and this will be the focus of our investigation," David Smith, deputy information commissioner, said in a statement on Friday.

Smith, whose office is the UK's independent authority to protect personal information, added: "We are concerned by any breaches of security particularly if they involve confidential banking details."

He said if UK firms use an outsourced call centre they are required to ensure security is adequate. If they do not, a company could be ordered to stop processing personal information outside the UK, Smith said.

A Channel 4 television programme "Dispatches" said on Thursday that criminal networks in India had offered British consumers' bank account details and other commercial information.

People were shown offering to supply credit card numbers, passwords and other information for as little as $15 and as much as $55 per customer. They said they could supply information on hundreds of thousands of people, obtained from a number of commercial call-centres.

Data for customers at most major UK banks were offered for sale, although the information was not obtained from bank call-centres but through call centres for certain mobile phone companies, whose customers had provided financial information.

"We are comfortable about the security of our own operations in India," a spokeswoman for Barclays Plc said.

The bank said its customers and other bank customers regularly needed to supply their bank or credit card account details to pay for goods and services at other call centres.

HSBC, Britain's biggest bank, said its data security had not been breached and no leak of customer data from its operations in India had been shown in the programme.

Mobile phone companies Orange and Hutchison Whampoa's 3 UK run one call centre each in New Delhi and Mumbai. Both firms said no customer data had been stolen from their centres.

"All credit and bank card data captured from our customers is encrypted and stored in the UK, under UK law, to ensure the highest levels of protection," 3 UK said in a statement.

CALL CENTRE BOOM

UK payments association APACS said the bank industry was concerned about the access to customer details shown in the programme, but noted the information was not sourced from bank call centres and every bank had strict security measures.

APACS said banks had anti-fraud guarantees so any customer who was an innocent victim of fraud would get their money back.

The National Association of Software and Services Companies, which represents the Indian call centre industry, said it appeared offences had occurred.

It said it had filed a report with Kolkata police, an investigation was underway, and it would soon file complaints with police in Delhi, Hyderabad and Bangalore.

Indian call industry officials said on Thursday the latest concerns could affect new business.

India's booming back-office sector -- which provides services such as handling customer requests and payroll accounting at a fraction of the cost in Britain -- is expected to grow by 27 per cent in 2006/07 and generate revenues of $8 billion, according to industry estimates.

But a string of fraud cases has raised concerns about the industry, which employs around 400,000 people.