The costs of the Department of Trade and Industry inquiry into the collapse of MG Rover have nearly doubled to £23,000 a day.

In reply to a question in Parliament from Norman Lamb, Liberal Democrat spokesman on trade and industry, Gerry Sutcliffe, minister at the DTI, said that the total spent was £1.6m at the end of September.

This compares with £1.09m paid to BDO Stoy Hayward and the firms' partner and lead investigator Gervase MacGregor at the end of August for the previous three months – a figure exclusively uncovered by Accountancy Age under the Freedom of Information Act at the beginning of November.

The DTI has said the inquiry is expected to take at least two years, however, many DTI-led inquiries have lasted longer.

Sutcliffe told Lamb that the accountant inspector had a team of junior staff working for him, 'retrieving, copying, logging and analysing documents'. 'The costs of the inspection are inherently front-loaded because of the need to obtain the records and financial information at the outset', he said.

'Both the secretary of state and the inspectors are intent on completing this inspection as quickly as possible, with due regard to the fairness procedures and to the thoroughness of the task', he added.

Lamb told The Times that inquiries such as this one had an 'enormous capacity to ratchet up costs'.

'The danger is that they go on for so long that the issue being investigated is lost sight of. It is important that a conclusion is drawn but not that the costs are disproportionately high for the subject.'