They are, “in negotiations:

JPMorgan Chase is in talks with the authorities to turn over customer money that disappeared from MF Global when the firm went bankrupt last year.

The development, announced this week by the trustee tasked with returning money to MF Global customers, suggests that a substantial sum of client funds is still sitting at JMorgan. The statement from the trustee, James W. Giddens, said that he and JPMorgan “are presently engaged in substantive discussions regarding the resolution of claims.”

What is going on here is that JP Morgan took money from MF Global for margin calls that came from customer accounts.

The reason that they are negotiating is because they knew that the money was dirty, because they knew that MF Global had no other source of liquidity, it’s why they made the margin call in the first place.

They did something similar in the collapse of Lehman as well.