On January 7, Monica Lewinsky, a White House aide, gave an affidavit denying that she had had an affair with the president.

She had been summoned by lawyers representing Paula Jones, who is suing Bill Clinton for sexual harassment.

The president is alleged to have told her to lie when making her statement to the lawyers.

Another White House aide allegedly taped a series of phone conversations in which Monica Lewinsky talks about how Bill Clinton and one of his lawyers asked her to lie about their relationship.

Paula Jones' team has talked to a number of female aides of President Clinton in the hope of trying to establish a pattern of sexual behaviour which would strengthen allegations that he sexually harassed Mrs Jones.

Her case could be overshadowed by the much more serious claim that President Clinton ordered a member of staff to commit perjury, if it should prove to be true.

Monica Lewinsky began working at the White House in 1995 before being moved to the Pentagon.

For much of that time investigators claim she had an affair with Mr Clinton which she described in graphic detail to a work colleague, unaware that the colleague was taping the conversation.