Defense attorney Ira Lee Sorkin's late father once had an account with Madoff. The lawyer also represented two Madoff-linked accountants in a securities case 17 years ago.

Madoff is expected to say he doesn't mind the potential conflict.

Prosecutors have sought a hearing Tuesday before Judge Denny Chin in federal court.

The court appearance is expected to be a warmup to Madoff's Thursday plea hearing when he is expected to plead guilty in the case. At least 25 investors have indicated they'd like to speak Thursday.

The 70-year-old Madoff was arrested in December and accused in a $50 billion fraud.