Some of Hillary Clinton’s closest aides, including her longtime adviser Huma Abedin, have been interviewed by federal investigators as the FBI probe into the security of Clinton’s private email server nears completion, U.S. officials briefed on the investigation tell CNN.

The investigation is ongoing, but so far investigators haven’t found evidence to prove Clinton willfully violated the law, the standard needed to bring charges, the U.S. officials say.

The officials say the interviews of Clinton and her aides would be a routine part of an investigation like this.

Get complete coverage of breaking news on CNN TV, and CNN Mobile.
Watch CNN live or On Demand from your computer or mobile device using CNNgo.