Provident Financial plc, the Bradford-based doorstep lender, today denied that projected losses of up to £20 million in its Yes Car Credit business had been triggered by hostile publicity in a BBC investigative programme.

The home credit group revealed that sales levels in the first five months of the year had plummeted by 26 per cent at Yes Car Credit. The company's shares plunged by six per cent yesterday after it disclosed that the division was poised to lose between £15 million and £20 million.

Earlier this year the BBC Whistleblower programme accused Provident of lying to customers and selling them potentially dangerous cars after filming at a branch in Croydon and secretly recording a training session. Provident said the problems identified by the undercover programme had been confined to Croydon where staff had been retrained.

Provident chief executive Robin Ashton said the programme had had a "very limited" impact on sales and added that the decline in sales had been similar in the months before the screening of the programme. Mr Ashton said that depressed market conditions "reflected consumer confidence and we believe our close competitors are seeing a similar sort of performance."

In the five months to the end of May, Yes Car Credit notched up a pre-tax loss of £4.6 million as the group came under additional pressure improved the quality and preparation of the vehicles it put up for sale. The firm's difficulties were compounded by a failure to sell optional products such as payment protection insurance and an inability to collect as many bad debts as last year. In its statement Provident added: "The performance of the group at this half year is likely to be below market expectations but only as a result of the poor performance at Yes Car Credit."

It said that a comprehensive improvement plan involving a string of management changes had been implemented to move the group back to profitability by 2006.

The disclosure prompted investment bank Dresdner Kleinwort Wasserstein to cut its forecasts for Yes Car Credit from losses of £2.7 million to a deficit of £18 million.