The bank where Bernard Madoff kept his clients' money is defending itself against allegations that it should have done more to stop his massive fraud.

JPMorgan Chase said in a court filing late Tuesday that it violated no federal rules and had no obligation to probe Madoff's investment scheme.

A court-appointed trustee sued the bank this month for $6.4 billion, claiming it suspected Madoff was a fraud but did almost nothing.

JPMorgan's court filing says that if the trustee were to get his way, it would impose "broad investigative duties" on banks that don't currently exist.

The bank also wants the case moved from bankruptcy court to district court. It says the suit is akin to a huge class action, more properly heard by a jury.