Guy Newey QC of Maitland Chambers and Gervase MacGregor of BDO were commissioned two months after the car-maker was plunged into administration in 2005, leaving 9,000 workers without jobs at its sites in the West Midlands.

This week a spokeswoman for the Department for Business Enterprise and Regulatory Reform said the inspectors are intent on 'completing this inspection as quickly as possible, with due regard to the fairness of procedures, and to the thoroughness of the task'.

'The inspectors have not been given a specific target date for the completion of their investigation. To do so might restrict the depth and thoroughness of their enquiry.

'While the inspectors are 'masters of their own procedures' as far as the investigation is concerned, they meet with officials regularly in order to monitor progress and to ensure that the momentum of the investigation is maintained.

'On their appointment the secretary of state asked the inspectors to report back to him as quickly as possible and in a form that will enable the report to be made public,' a spokeswoman said.

The inquiry came under fire from parliament in March after it was revealed that the investigation bill had already reached £8m.

The DBERR revealed the costs of the inquiry, as at the end of July at £7,838,156 plus disbursements of £370,551 and VAT of £1,436,163.

The figures released suggest the cost accumulation from a spend on the inquiry of approximately £370, 000 per month.

This cost is now in excess of the £6.5m loan, which government granted to allow the company to continue trading a week after it went into administration in April 2005.

Last year the Public Accounts Committee also revealed that taxpayers were paying a £270m bill for Rover's 2000 to 2005 operations.

Neither Newey nor MacGregor were available for comment.

In the meantime, the Accountancy Investigation and Discipline Board is investigating the conduct of Rover's auditors and advisers, Deloitte.

The AIDB began its probe of Rover's 2003 accounts in 2005, at the request of the Secretary of State for Trade and Industry, Patricia Hewitt.

For further reading click here