Why is Benghazi still a big issue for Hillary Clinton?

On Thursday Hillary Clinton will testify in front of the House Select Committee on Benghazi. It is the second time she has been called before Congress to discuss the attack on the US consulate in Libya, which took place during her tenure as secretary of state.

The Republicans who run the committee say the American people deserve to know about the night that killed four US citizens, including Ambassador Chris Stephens.

Mrs Clinton is now the front-runner for the Democratic nomination for President, and her supporters say the hearing is an expensive, elaborate fishing expedition less interested in the facts than in doing her political damage.

How did it get to this point? The BBC's State Department Correspondent Barbara Plett Usher looks at the complicated history between Mrs Clinton and the committee.

Produced by Franz Strasser and Suzanne Kianpour.