A senior Republican congressman said yesterday his committee is investigating whether the fugitive financier, Mr Marc Rich, made donations through others to former President Clinton's presidential library.
Mr Dan Burton of Indiana, who heads the House of Representatives Government Reform Committee, also told Fox News he had been the target of death threats and would have extra security with him as long as the investigation into the controversial pardon of Mr Rich continued.
"There have been threats and we will just deal with them as they occur", Mr Burton said. "We have security with me and we are going to be very careful during the investigation."
Mr Burton, a long-time critic of Mr Clinton who has spearheaded a number of probes of the former first family, said he expects his probe to proceed more easily this time because he no longer is confronting a reluctant Justice Department.
"Now that we don't have all of those roadblocks in front of us we're getting information that we haven't gotten before", he said.
The Manhattan US attorney has begun a criminal probe into the ex-president's pardon of Mr Rich and his partner, Mr Pincus Green, the most controversial of the actions Mr Clinton took on his last day in office.
The investigation in New York and two congressional investigations have expanded in recent days to include other controversial pardons, including ones involving Mr Clinton's half-brother, Mr Roger Clinton, and Senator Hillary Clinton's brother, Mr Hugh Rodham, who received $400,000 for preparing two clemency petitions granted by the former president.
Mr Rich, who fled to Switzerland 17 years ago, will not face prosecution on more than 50 counts of racketeering, wire fraud, income tax evasion and illegal oil trading with Iran.
Mr Burton said his panel would be focusing on whether the Clinton library received funds in return for Mr Rich's pardon.
Clinton library officials have refused to disclose the donors to the $200 million library and foundation to be built in Little Rock, Arkansas.
Mr Burton noted there had been "conduit payments to the campaign" from as far as Indonesia and China in 1996, and said: `This is a mode of operation that we have seen in the past and it may have been `get some more money in'. That is . . . something we are looking at."
Mr Rich's former wife, Ms Denise Rich, donated more than $1 million to Democratic causes and $450,000 to help build the library.
Senator Arlen Specter, a Pennsylvania Republican heading the parallel Senate Judiciary Committee probe, told CBS's Face the Nation programme he would like to hear from Mr Clinton, voluntarily, before his panel.
Mr Specter also said his investigation was expanding to include Mr Rodham's and Mr Roger Clinton's participation, and that Senator Clinton, who has denied knowledge of any of the pardon proceedings, "is going to have to decide" whether she also will testify.
Mr Burton said he doubted his panel would be able to get any of the pardons reversed and that he wasn't sure his probe would turn up evidence that money was paid out for pardons.
"Even if there wasn't criminal activity, it certainly was unseemly to pardon the No 6 wanted fugitive in the world", he insisted.