Businessman Neil Mitchell said he blew the whistle to the Serious Fraud Office over the state of Torex Retail's accounts, it was reported yesterday.

Mr Mitchell, who was asked to step down as chief executive of the Oxfordshire-based firm, told the Financial Times he was the "leader of the Torex whistleblowers".

He said he would be seeking his reinstatement under legal protection afforded to people who approach the authorities with information.

There were a total of four whistleblowers who had voiced concerns to the Financial Services Authority and the London Stock Exchange as well as the SFO, Mr Mitchell said.

The SFO said it had searched three properties - two in Oxfordshire and one in Warwickshire - with the City of London Police, but would not say whose homes were raided.

The company employs 65 people at its headquarters in Range Road, Witney, and 53 more in Banbury.

Spokesman Ginny Pulbrook said the company would not comment on Mr Mitchell's version of events.

The company said on Wednesday that both Mr Mitchell and chairman and company founder Christopher Moore, from Hook Norton, were stepping down.

Torex issued a profit warning last week and asked for its shares to be suspended.

Auditors Deloitte and accountants KPMG have been called in to look at the accounts of the firm, which produces computer software for shops' checkouts, tills and stock books.

Ms Pulbrook said it would be "weeks rather than days" before the result of this investigation was known.

Torex Retail is worth about £200m and boasts a turnover in excess of £100m a year.