Ms Coleen Rowley, the FBI agent who accused the bureau of mishandling warning signs before September 11th, faces a Senate hearing on US counter-terrorism efforts later today.
Ms Rowley shocked the FBI last month by sending a 13-page letter to Director Mr Robert Mueller questioning his handling of information. It accused him and other top FBI officials of "skewing the facts" when commenting on how much the FBI knew before the September 11th attacks on the US.
The Minneapolis-based agent will be making her first public statements since sending her letter when she appears before the Senate Judiciary Committee's oversight hearing focusing on the Justice Department's counter-terrorism efforts.
She is one of three witnesses expected to testify at the hearing, which is taking place as the intelligence committees of the House and Senate conduct a joint inquiry into the failure of US intelligence to stop the September 11th attacks.
Mr Mueller - who has acknowledged that the FBI had mishandled possible clues before the attacks - will appear in the morning session, Ms Rowley is scheduled to appear in the second session.
Senators are expected to raise issues like the FBI's reorganisation, controversial new guidelines issued by Attorney General John Ashcroft which give FBI agents more freedom to conduct domestic surveillance and Mr Ashcroft's new plan to start fingerprinting and registering about 100,000 foreign visitors a year as part of the anti-terrorist effort.
Mr Mueller will also likely be asked about some of the concerns Ms Rowley raised in her May 21st letter. In that letter she complained that FBI headquarters should have approved a request from its Minneapolis office for a search warrant involving Mr Zacarias Moussaoui, who was being held in August after arousing suspicions at a Minnesota flight school.
Mr Moussaoui was in custody in Minnesota when the September attacks occurred, but was charged in December with conspiring to carry out the September 11th attacks. Authorities suspect he intended to join the 19 men who hijacked four planes that day, but agents did not receive a search warrant in time.
Mr Mueller will also likely be asked why the FBI failed to act after one of its agents sent a memo two months before the September 11th attacks warning that Middle Eastern men were taking flight lessons and urging an investigation.
