A search warrant that allowed police to raid a Preston accountancy firm in connection with an Asian family being investigated for an alleged multi-million pound counterfeit clothing and money laundering scam should have been issued, London's High Court has ruled.

Lord Justice Keene, sitting with Mr Justice Griffith Williams, backed a string of warrants that were granted during a police and Revenue and Customs (HMRC) operation targeted at Arif Patel, Munaf Patel and Faisal Patel and the Preston-based companies they control.

The court heard that eight search warrants were issued on March 31, 2008, and a ninth on April 3, by Judge Brown at Preston Crown Court.

They were executed on April 3, with police searching the solicitors offices of Hill Dickinson LLP, Liverpool, as well as those of accountants, Hindocha & Co, in Harewood Road, Preston.

Officers also searched Faisal House, Olivers Place, Preston - the premises of Faisaltex Ltd, Faisaltex Manufacturing Ltd and Faisal Imports Ltd - and Patel family homes in Sharoe Green Park and Sharoe Green Lane, Preston.

Lord Justice Keene said that, between March 2004 and April 2007, HMRC seized 39 consignments of clothing imported into the UK, all of which were found to contain counterefeit items.

The estimated "losses" to the 35 well known brand companies whose goods were found to have been faked was £1m per consignment.

Documentation found with the goods "related, allegedly, to various companies directly owned and operated by members of the Patel family...or companies that could be linked to the Patel family and their businesses", said Lord Justice Keene.

"The 39 consignments seized are regarded by the police and HMRC as a very small proportion of such consignments, which in all amounted to over 600 containers," the judge added.

"It was believed by those authorities that the three Patel brothers and their companies had been involved in the counterfeiting trade since the late 1990s, both by manufacture and by importation."

He added that HMRC were also investigating allegations of false export declarations, which enabled the exporter to reclaim VAT, with losses to the revenue of £45m.

When Judge Brown was asked to issue the warrants, he was told that there was reason to believe a number of criminal offences had been committed.

The brothers, as well as Faisaltex Ltd, Faisaltex Manufacturing Ltd, Faisal Imports Ltd, and accountant, Anil Hindocha, trading as Hindocha & Co, launched a High Court challenge, arguing that the warrants were unlawfully issued and, when they were executed, the police had seized an "excessive" amount of material and had acted "oppressively".

Lord Justice Keene agreed that the warrant granted against Hill Dickinson, who were not a party to the High Court case, should not have been issued, observing that there was no "rational basis" for Judge Brown to have done so.

However Lord Justice Keene upheld Judge Brown's decision to issue of the other warrants, and dismissed arguments they were "invalid".

He also dismissed suggestions that too much material had been seized, and declined to join the Patels' parents - Bibi and Umarji - as claimants in the case.

It means that applications to have all property seized in the raids returned were refused, although documents taken from Hill Dickinson's offices will have to go back to the solicitors.