National Gallery in London in the lens for new documentary

A documentary portrait of London's National Gallery is emerging as a prime attraction as it opens up at film festivals around the world.

The three-hour film is a fly on the wall account of life inside the institution from veteran US filmmaker Frederick Wiseman.

There are no talking heads or voice over - the film is just an edited presentation of what his camera has captured.

National Gallery will be shown at both the New York and London Film Festivals next month.

Talking Movies' Tom Brook reports.