The report led by Legal Services Complaints commissioner Zahida Manzoor was critical of the way the LCS handled Coal Health Compensation complaints.

"The findings contained in this report show that different financial outcomes are being achieved for miners depending on a bewildering array of variables including whether a Member of Parliament is involved, the LCS caseworker handling the complaint and the cooperation of the solicitor's firm being complained about," Manzoor said.

The Coal Health Compensation Scheme was set up to compensate miners for Chronic Obstructive Pulmonary Disease (COPD) - a respiratory disease (chronic bronchitis and emphysema) resulting from the dusty conditions; and Vibration White Finger (VWF) - a disease caused by using vibrating tools.

Under the scheme potential claimants could apply for compensation via their legal representative and the Government met the cost of the claimant's legal representation, where these claims were successful.

The scheme provided solicitors with detailed procedures that had to be followed when dealing with claims and how much solicitors would be paid for each successful case.

However, some solicitors deducted success fees from miners' compensation awards in addition to the costs they would receive from the Department of Trade and Industry, to compensate for the fact that they would not be paid in unsuccessful cases. However, this often meant the solicitor was being paid twice for the same work.

The deduction of success fees was common until 1999 when most, though not all, solicitors stopped the practice after claims handling agreements were introduced.

Those cases can now be brought to the LCS for further compensation, and the services handling of those claims is now under scrutiny in the report released Monday.

The four key findings of the report focus on the two processes LCS caseworkers can use to resolve complaints - conciliation and adjudication.

The report identified that although most miners were more likely to receive greater compensation through adjudication some LCS caseworkers were recommending conciliation at levels of redress that were not appropriate to the circumstances of the miner's case.

"I highlight the case of six individual miners who, in 2007, have shown real persistence in their complaints.

"Despite being encouraged to conciliate by the LCS they refused, and insisted that their complaints should be investigated and adjudicated. Through their persistence, each of these miners has, on average, correctly received an additional £1700 compensation from their solicitors," Manzoor said.

"Overall, without taking the corrective action I am proposing, miners' complaints could become an Achilles Heel for the LCS.

"These problems mean that [the LCS] is at risk of damaging its own reputation with the legal profession by asking them to foot the bill to pay consumers additional compensation for its own poor service."