A solicitor who was cheated out of hundreds of thousands of pounds in a money laundering scam is urging police to launch an investigation into one of the world's biggest banks.

John McArdle was the owner of the PMB Motors car showroom, in Darlington, which was systematically fleeced by its crooked financial director Mary Blair.

She was sentenced to five years in jail by a judge at Teesside Crown Court last year.

Blair admitted stealing £819,200 from PMB Motors - later taken over by South Cleveland Garages - between July 1997 and June 2002. Her nephew, Christopher Grimes, whom she persuaded to launder £683,481, was jailed for 15 months.

The cash was ultimately used to prop up the flagging wedding dress firm Manhattan House, operated by Blair in Darlington and Newcastle.

The company, originally called Chloe Bridal Wear, eventually went into receivership and was sold for £16,000.

Now, Darlington-based solicitor Mr McArdle is calling for an inquiry into his claims that HSBC Bank may have failed to comply with regulations requiring staff to report any unusual transactions.

He said: "Here we have a situation where Christopher Grimes, who was just 18 and employed by Mary Blair on a YTS wage, was regularly paying thousands of pounds into his own account at HSBC in Newton Aycliffe - and then immediately transferring all but £100 to Mary Blair and her companies.

"Yet, despite the fact that he was just a teenager on a minimum wage, the bank allowed these transactions to continue.

"Since 1993, banks like HSBC are required to obtain sufficient information about their customers in order to determine any inappropriate activity - and here we have this teenager typically paying in cheques for, say, £8,900 and then being paid out a cheque for £8,800."

He added: "I asked HSBC to prove to me that they had complied with the regulations, but they have not done so."

Mr McArdle has made a formal complaint to Durham Police and also asked the Financial Ombudsman to investigate.

Detective Inspector Colin Gibson, head of the police's economic crime unit, said last night: "We have received a complaint against HSBC and it is a matter that is currently being looked at."

However, the Financial Ombudsman said it would not be holding an inquiry.

A spokeswoman said: "The complaint was in the name of the showroom and, as that had a turnover of more than £1m, we can't look at it.

"Also, you can complain about your own bank, if you are the true owner of a cheque, but he (Mr McArdle) hasn't got a relationship with HSBC."

Despite several requests by The Northern Echo, nobody from HSBC was available to comment on the matter.