A small north-east conveyancing firm has become the latest victim of telephone bank scammers, the Solicitors Regulation Authority revealed today, calling for extra vigilance across the sector.

According to the regulator the firm 'lost a significant amount from its account'. The crime, which relied on 'social engineering' to gain access to bank accounts follows two serious telephone scams in March this year.

In each case callers asked for 'challenge and response' codes, which are then used to authenticate payments and in some cases digital banking logon and password credentials.

Four firms were targeted in this way in November last year.

Robert Loughlin, SRA executive director of operations and quality, said: 'We are very concerned about this continuing activity. The fraudsters are highly sophisticated in their approach and their script makes them sound as though they are genuinely who they say they are.

'All firms should ensure that their own internal systems for guarding against scams are up-to-date and that staff know how to implement them.'

He said that bona fide banks will never ask for passwords or account related details over the phone.

To validate callers, firms should contact somebody they already know at the bank, using a separate telephone line, for example a mobile: there have been examples of the scammers keeping telephone lines open, to intercept an outgoing call, the SRA said.