Accounting irregularities at scandal-hit WorldCom date back as far as 2000, according to Republican congressman Billy Tauzin.

Speaking on ABC's "This Week" TV show in the US yesterday, Tauzin said that two employees had raised concerns about accounting issues.

Another whistleblower, Troy Normand based in the US, also highlighted concerns about the company's accounting policies.

However, Tauzin said that internal documents showed that management had tried to sweep the concerns under the carpet.

Tauzin told the programme: "The documents also reveal a strange pattern of people inside the corporation discovering it, trying to do something about it and ultimately failing until recently."

The Guardian reports that another whistleblower could be about to dish the dirt. A British woman claims she complained to the Department of Trade and Industry in 1999 about WorldCom but was horrified when the DTI failed to act.

Geraldine Kelly, who worked for the company for less than a year, is now represented by publicist Max Clifford and is reportedly looking to sell her story to a newspaper.

Separately, a group of 25 banks filed a lawsuit on Friday alleging WorldCom defrauded them out of $2.5bn.

The unsecured loan was bagged just six weeks before WorldCom admitted that it had made a $4bn slip in its accounts.

The banks said had they known of the accounting irregularity they would never have handed over the cash. ®