See here for the film: https://www.youtube.com/watch?v=ZjydIhYPfN0.
A live show by Ben Emlyn-Jones at the High Wycombe Paranormal Meet-up Group. A brand new lecture, never before performed, entitled Helen Duncan- the Witchcraft Trial Seventy Years On. Apologies for the poor framing.
See here for background: http://hpanwo-tv.blogspot.co.uk/2014/07/helen-duncan-most-dangerous-psychic-in.html.