updates
7:25 AM PT -- Joseph McBride, lawyer for the Tate brothers, is blasting the investigation ... telling TMZ it's a "pathetic delay tactics by a group of weak lawyers running from a fight in the Florida Defamation Case, because they know the evidence is overwhelmingly on our side."
He adds ... "The SDNY is subject to Washington. Washington is not involved. We are not worried. Nothing changes. Our march to victory continues."
The Tate brothers' legal issues in the U.