More could have been done by the regulator but it is unlikely to have made any difference.

That’s the conclusion of a Financial Services Authority-commissioned report into a miss-selling saga.

Energy company Scottish Power offered cash-back incentives for customers who took out extended warranties on electrical goods from 1997.

But some hundreds of thousands of consumers, many of them pensioners and some living in the Isle of Man, are still waiting to receive their money.

Between 1997 and 2001 extended warranties were offered by Scottish Power to customers who bought white goods such as TVs, fridges and cookers at its retail outlets. Cashback warranties were sold on the promise that if you didn’t claim within five years you would get your cash deposit back.

The average cost of the cash back potentially reclaimable was £140.

But the scheme went under in 2004, three years after Scottish Power sold its retail business to Powerhouse Holdings Ltd. Thousands of people started calling in their cashback but the warranties were never paid, meaning 625,000 customers lost out on a combined £75m.

An independent review by Charles Flint QC was launched in March last year on the role of the Insurance and Pensions Authority in the failure of island-authorised Powerhouse Insurance Ltd, which insured the warranty cash back liabilities and had been acquired by Scottish Power in 1996. Now a report, which includes Mr Flint’s key findings and the FSA’s response, has been presented to the Treasury Minister.

FSA chairman Geoff Karran notes: ’This is a complex case in which the material events occurred between 13 and 20 years ago.

’As is often the case in these matters there is always more that could have been done by all parties involved but as confirmed by Mr Flint QC, certainly from a regulatory point of view, it was unlikely to have made any difference in the end to the demise of Powerhouse Insurance Limited.’

Mr Flint found no evidence that the affairs of Powerhouse Insurance were mismanaged by Scottish Power, although the reserves to meet the cashback liabilities later proved to be inadequate.

He also found that the very serious allegations of impropriety made by the liquidators against Powerhouse’s directors are ’baseless’.

But he concluded there had been regulatory failings.

He said regulatory regime in force between 2001 and 2003 did not provide a supervisory system which adequately protected the interests of policyholders and the IPA failed to consider the risks arising from the large exposure relating to financing advanced to the Powerhouse Group.