Mrs. Clinton was unavailable for comment.
Former top Democratic fundraiser Norman Hsu has told a federal judge in Manhattan he will plead guilty to 10 counts of wire and mail fraud.
The 58-year-old Hsu was indicted in 2007 on charges of cheating investors of at least $20 million in what prosecutors say was a huge Ponzi scheme. He had been scheduled to go on trial Monday.
The government also says he made illegal donations to politicians including Hillary Rodham Clinton. Her Senate campaign later returned money linked to him.
Prosecutors say he pressured his victims to contribute to political candidates as a way to raise his public profile so he could attract more investors.