The alleged ringleader of the gang of eight was customer service adviser Imtiaz Khan, 28, who had access to confidential computer records while he worked in the Halifax bank's call centre in Leeds.

Leeds Crown Court was told that Khan used confidential information gained from customer computer records to tamper with at least 105 accounts.

The court heard that Khan searched the bank's database for cards not regularly used and recorded personal details including names, security codes and passwords.

A gang member would then call the bank posing as the customer and use the information to change the account address. A new card and PIN would be requested and used to withdraw cash. The cards were also used for fund transfers and to purchase goods.

The gang, which consisted of Khan's family and friends, are alleged to have opened bogus accounts with Capital One to transfer money and made the minimum monthly payments on the Halifax credit cards to avoid suspicion.

The gang were arrested in police raids in April 2003. Police found £66,000 in cash and over 30 new cards at the home of Khan's brother.

All eight deny conspiracy to defraud the Halifax and Capital One banks out of over £420,000 between June 2001 and April 2003.

The trial continues.

In January City of London Police charged a former Lloyds TSB employee with corruption and theft after he allegedly helped criminal gangs set up fraudulent bank accounts.

Seevaratnam Sivathasan, 33, was an assistant manager in the Wandsworth high street branch of Lloyds TSB in London, in 2003 when the alleged offences took place.

In November the Financial Services Authority (FSA) repeated warnings that criminals were applying for jobs in financial services firms in order to gain access to sensitive customer data and said there was evidence that organised crime groups deliberately placed agents inside banks to commit crime, particularly identity theft.