I think the feds can "ask" their brass politely to STFU. Which request would be followed by the ESPN brass's favorite response, "And exactly what is in it for us if we sit on this information?" Followed by the feds offering, "If you don't F up our ongoing investigation, we will see to it that you get to break this MFer and that you get the juicy ****."
But if all that is legit, ESPN is playing a very dangerous game. TMZ could blow the roof off this MFer tomorrow and there would be the werl wy leaduh looking like Time when Drudge broke the story on sideways dick hosing his man juice on chunkystein's blue dress.