NY Times new article says DC Grand Jury subpoenas involve Flynn :
"WASHINGTON Robert S. Mueller III, the special counsel investigating Russias attempts to disrupt last years presidential election, has issued subpoenas from a Washington-based grand jury in recent weeks, according to several lawyers involved in the case.
At least some of the subpoenas were for documents related to the business dealings of Michael T. Flynn, the retired general who briefly served as President Trumps national security adviser. Mr. Flynn is under investigation for foreign lobbying work, as well as for conversations he had during the transition with Sergey I. Kislyak, who was Russias ambassador to the United States.
Mr. Muellers team is broadly investigating whether any Trump associates colluded with the Russian government in its attempts to disrupt the election. It is unclear whether the subpoenas issued in recent weeks relate to other members of Mr. Trumps campaign who have been a focus of the Mueller investigation, including Paul J. Manafort, the former campaign chairman.
A grand jury based in Alexandria, Va., began issuing subpoenas in the Flynn case months ago. Mr. Mueller took over the investigation in May and assembled a team of prosecutors in an office in downtown Washington. Mr. Mueller has not impaneled a special grand jury, the lawyers involved in the case said, and has decided instead to use one of several grand juries that regularly sit in Washington."
https://www.nytimes.com/2017/08/03/us/politics/robert-mueller-russia-investigation-grand-jury.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=first-column-region®ion=top-news&WT.nav=top-news