The exact nature of the subpoena – served on 26 May 2022 and first obtained by the Guardian – and whether it means Trump himself is under criminal investigation for January 6 could not be established given the unusually sparse details included on the order.

But certain elements appear to suggest that it is related to a new investigation examining potential criminality by the former president and, at the very least, that the justice department is expanding its inquiry for the first time into Trump and his inner circle…

The confounding aspect of this grand jury subpoena, according to three former assistant US attorneys who spoke on the condition of anonymity, is that targets of investigations are rarely subpoenaed. And “process” charges such as contempt do not require subpoenas for documents.

But the fact that Trump is specifically named in the subpoena – a reference that the justice department would not have made lightly – and the specific requests for Navarro’s communications with Trump could indicate that this is a criminal investigation examining Trump.