Congressional investigators prepared subpoenas today to force three of former President Bill Clinton's top aides to testify on White House deliberations over the last-minute pardon of fugitive billionaire Marc Rich.
The House of Representatives Government Reform Committee is one of two congressional panels looking into claims the pardon was linked to political donations from Rich's former wife Denise.
It will subpoena former chief of staff Mr John Podesta, adviser Mr Bruce Lindsey and counsel Ms Beth Nolan to testify at a March 1st hearing.
As federal officials in New York confirmed they had started a criminal inquiry into the pardon the committee also asked Marc Rich and Mr Clinton to waive any privilege rights for documents and communications regarding the pardon.
The committee agreed yesterday to a Justice Department request to hold off trying to immunise Denise Rich to force her testimony.
Prosecutors feared an immunity grant for Rich - who has donated more than $1 million to Democratic causes - would interfere in the criminal investigation.
A CBS News report said Ms Rich was willing to testify to the panel as long as she was granted immunity. But a committee spokesman said the panel had not heard from her and "the offer doesn't change a thing for us."
"Until we hear otherwise from the Justice Department, we will not extend immunity for Mrs Rich," spokesman Mark Corallo said.
"The committee will not impede the US attorney's investigation."
US Attorney Mary Jo White and the FBI confirmed the federal investigation in a brief statement yesterday.
On his show last night CNBC host Geraldo Rivera quoted Mr Clinton as saying: "There's not a single, solitary shred of evidence that I did anything wrong or that Marc Rich's money changed hands. There's certainly no evidence that I took any of it."
The Washington Postreported Mr Rivera - a long-time friend of Mr Clinton's - read notes from the conversation, quoting Mr Clinton as saying he was blind-sided by the controversy over the pardon.
The House panel was also likely to call Lewis Libby, Vice President Dick Cheney's chief of staff and a former lawyer for Rich, to testify at the March hearing, committee sources said.