WASHINGTON (AP) — FBI agents probing whether Hillary Clinton's use of a private email server imperiled government secrets appear close to completing their work, a process experts say will likely culminate in a sit-down with the former secretary of state.

The FBI has already spoken with Huma Abedin, a Clinton confidant who was among the Democratic presidential front runner's closest aides at the State Department. The lawyer for former Clinton chief of staff Cheryl Mills says she is also cooperating with the investigation.

That signals, former Justice Department officials tell The Associated Press say, that agents will probably seek to interview Clinton in the near future, if they haven't already. The FBI's standard practice is to save questioning the person at the center of an investigation for last. Clinton has denied any wrongdoing.