The Lord Chancellor's call last night for the trial transcripts increased the likelihood of Government action.
MPs on the Commons Culture and Media Select Committee yesterday repeated their long-standing demand for the Government to outlaw the practice, after trial judge Mr Justice Butterfield described the payment as "a highly reprehensible state of affairs" in his summing up to the jury.
Llin Golding, a Labour member of the committee, said: "I think payments by newspapers really do raise some very serious questions about how they influence the mind of a jury."
The Press Complaints Commission said yesterday it would be investigating the newspaper's behaviour in the case.
The News of the World yesterday said it had no inkling the woman would appear in a criminal case when it made the deal.
The Government has been under pressure to act on witness payments since the Rosemary West trial, when it emerged that 19 witnesses had made deals with the media.