Federal prosecutors in Detroit say there's an urgent need to get documents from the former financial empire of John Bravata, a Michigan money manager accused of fraud.
The government says a five-year statute of limitations on possible crimes expires in spring.
A receiver overseeing what's left of Bravata Financial was given a grand jury subpoena in February but nothing has been produced because Bravata believes there may be privileged information that shouldn't be shared.
Bravata said Monday that exercising his legal rights is not a "stall tactic."
His Southfield-based companies were shut down in 2009 after the Securities and Exchange Commission filed a civil lawsuit accusing him of a $53 million fraud.
He says he was invested in dozens of real estate parcels and denies any fraud.