All I can find is that Burgh Island is closely linked to Agatha Christie, as it served as the inspirational setting for both "And Then There Were None" as well as Hercule Poirot mystery "Evil Under the Sun". The 2002 TV adaptation of Evil Under The Sun used the island as a filming location.
Several scenes from the BBC’s 1987 dramatisation of Christie’s story Nemesis were shot in the Burgh Island Hotel, as it was felt that the location was ideal for the film.
I would have thought that the only option would be to look at the actual film credits to see where it was filmed.
Hope this helps.