Explainer: How much of the Mueller report must US attorney general disclose?

Now that Special Counsel Robert Mueller has submitted the report on his investigation of Russia’s role in the 2016 US election, Attorney General William Barr must decide how much of the document - if any - to make public.

Justice Department regulations governing special counsels adopted in 1999 give Barr, the top US law enforcement official, broad discretion in deciding how much to release to Congress and the public. Barr, in his January Senate confirmation hearings after being nominated by Trump, promised to “provide as much transparency as I can consistent with the law” - a pledge that still gives him a lot of wiggle room.