Alfred Hitchcock's lost documentary about the horrors of the Holocaust is to be screened in full for the first time.

The legendary moviemaker created the documentary using footage filmed during the liberation of Bergen-Belsen concentration camp in Germany in 1945, and Hitchcock was reportedly so traumatised by the shocking scenes, he took a week off work to recover.

The project, originally titled Memory of the Camps, was eventually shelved, and the film reels were given to the Imperial War Museum in London.

Some of the documentary was later cobbled back together and an incomplete version was screened at the Berlin Film Festival in Germany in 1984 and broadcast on American Tv a year later (85).

Memory of the Camps has now been revived and completed with the addition of a previously missing roll of film as part of a 2015 project to mark the 70th anniversary of occupied Europe's liberation following the Second World War.

The movie will air in Britain in 2015, along with a documentary about the restoration called Night Will Fall, which will also be shown at film festivals and in cinemas.