A Pakistani businessman accused of illegally funnelling tens of thousands of dollars to the political campaigns of US senators Hillary Clinton and Barbara Boxer surrendered to the FBI on a year-old indictment on Tuesday, then collapsed in Los Angeles federal court, Los Angeles Times reported on Wednesday.

    Looking tired and disoriented, Abdul Rehman Jinnah, 56, complained of chest pains and began shaking an hour into a contentious bond hearing before US Magistrate Judge Patrick J Walsh. The judge interrupted the hearing for nearly 30 minutes while paramedics attended to Jinnah. After Jinnah's condition was stabilised and he was taken to a local hospital for an examination, Walsh set bond at $300,000.

    The drama unfolded shortly after Jinnah, who has a history of heart problems and diabetes, flew back to the US from Pakistan to answer charges by a grand jury that he engineered illicit donations to Ms Clinton's political action committee and Ms Boxer's 2004 re-election campaign. Officials from both campaigns have said they were unaware of the alleged wrongdoing and returned the contributions.

    At Tuesday's hearing, Assistant US Attorney Dennis Mitchell urged the judge to deny Jinnah bond, arguing that he was a tremendous flight risk with a long history of financial misconduct that included five bankruptcy filings that had been dismissed by the courts.

    Mitchell said authorities suspected that Jinnah returned to the US to face federal charges only because the government had initiated travel restrictions that made it increasingly difficult for the businessman to travel overseas. He could flee again if he believes he will be imprisoned, Mitchell said.

    But Jinnah's attorney, former federal prosecutor Douglas Fuchs, said that was absurd, noting that his client had voluntarily surrendered and faced only one to two years in prison if convicted.

    Born in Pakistan, Jinnah immigrated to the US in the late 1980s and settled in Northridge. Over the next decade, he tried his hand at a string of businesses and left a trail of angry creditors and former business partners. But by 2004, Jinnah had positioned himself as a point man who could help the Democratic Party tap the increasingly affluent Pakistani American community for campaign funds. He and his family personally contributed $122,000 to Democratic candidates and organisations that year and held events for Ms Clinton and Ms Boxer at his home.

    Stuart Schoenburg, 76, a Tarzana television producer charged as Jinnah's co-conspirator, has pleaded guilty to a misdemeanour count and is awaiting sentencing.