U.S. District Judge Amy J. St. Eve said she grew concerned after learning that Rezko received $3.5 million from a company in Lebanon; he had said he had no income. St. Eve said she feared Rezko could be a flight risk.

The real-estate developer and fast-food magnate was arrested yesterday at his home in Wilmette. The judge ordered him into custody and scheduled a hearing today at which Rezko's attorneys will try to get bond reinstated.

Rezko has pleaded not guilty to fraud, attempted extortion and money-laundering, and is scheduled for trial Feb. 25. He is accused of pressuring businesses seeking work before two state regulatory boards to make campaign donations and payoffs.

Rezko had long been a fund-raiser for Gov. Rod Blagojevich and Obama, the senator and presidential candidate. Neither Democrat has been accused of wrongdoing.

Obama has said he had no indication of problems with Rezko when he accepted thousands of dollars in campaign contributions. When prosecutors unsealed their charges against Rezko in 2006, Obama gave $11,500 in Rezko contributions to charities.

Obama has since sought to distance himself from Rezko, even as rival Hillary Rodham Clinton invoked Rezko's name and his "slum-lord business" during a debate last week.

The Obama campaign declined to comment on Rezko's arrest yesterday.

Federal prosecutors say Rezko was deceptive in leading St. Eve to grant bond by claiming in April 2007 that he had no income and was instead living off the generosity of friends and relatives.

Defense attorney Joseph Duffy said, "There isn't anything that suggests flight." He said Rezko, a U.S. citizen born in Syria, had returned from overseas to face the charges against him.

Separately, Rezko faces federal charges alleging he swindled General Electric Capital Corp. out of $10 million in connection with the sale of two pizza restaurant chains.

Last week, it was learned that a Rezko associate had donated $10,000 to Obama's Senate campaign using money from the alleged pizza scheme. Obama's campaign then sent $40,000 in Rezko-related contributions to charity.

Earlier this month, Obama gave to charity more than $40,000 in past political contributions from seven individuals with ties to Rezko.

Obama also has had to answer questions on how Rezko became involved in the purchase of the Obama family home, and other ties to Rezko going back over 15 years.