Could he already be in custody?
This is pure speculation ... but I don’t think actual criminal investigations like for their targets to be called before Congress.
” but I don’t think actual criminal investigations like for their targets to be called before Congress”
Congress is superior to any investigator. Since congress can defund them and pass a law closing down the investigator’s office. Congress can abolish the FBI and impeach any judge who impedes this.
So yeah, even if investigators don’t like it, Congress is first if it wants to be. You don’t let the DOJ tail wag the dog.