Codenamed Operation Barber, specialist police search teams and DTI investigators raided the premises of companies across Nottinghamshire, Derbyshire and Leciestershire, looking for evidence of fraudulent trading.

Companies searched included manufacturers, wholesalers and storage premises. Fourteen of the 30 companies have already ceased trading with combined debts of more than £10m.

The operation – the largest of its kind – centres on a series of frauds in which it is alleged that companies set up lines of credit to buy goods – and then went into liquidation having sold the goods without paying creditors.

Enquiries into the alleged frauds began with an investigation by police into Lincolnshire firm, Palamino Ltd, which dealt in timber and household goods. This led to a conviction and four-year prison sentence for the director in 2000.

DTI chief investigation officer Chris Duggan said the main objective was to maintain confidence in British business.

“By conducting this type of operation, we will show fraudsters of all types that the DTI is taking very positive steps to show there is no hiding place,” he said.

“This is an ongoing investigation and we will be executing further warrants.”