AS WikiLeaks founder Julian Assange marks a year holed up as a guest of the Ecuadorian embassy in London, and another secrets case steals the headlines, Oscar-winning documentary maker Alex Gibney once again displays his trademark perfect timing with a gripping if somewhat bloated documentary.

Blending talking heads with compelling visuals, a fresh picture emerges of heroes and villains, bravery and breathtaking naivete, friendships and spectacular fallouts. If the power of the picture overall is lessened by too light an editing touch in the middle, allowing information overload to set in, it is a forgivable flaw.

As it should be, Gibney's film is as much a documentary about US intelligence officer Bradley Manning, the leaker, as it is about the man who lead the organisation to which he passed information on, among other matters, the actions of US forces in Afghanistan and Iraq. As Gibney (Taxi to the Dark Side, Mea Maxima Culpa) sets out the story, almost everything you could want is here, from interviews with former high-ranking officials in the US government to those close to Manning and Assange, or as close, in the latter case, as it was possible to get.

There are real interview coups here. The notable omission, though, is a one to one with Assange himself, though plenty of archive footage is used. Even then, Gibney has a good, make that jaw-dropping, reason for its absence. This director might not have got his man in this case, but he certainly knows how to nail a story.

Tuesday, 6.10pm; Wednesday, 8.20pm, Filmhouse.

✶ ✶ ✶ ✶

Edinburgh International Film Festival