Interview by Leonard Maltin (?) with the actor who played the dead body

Hi Blow Up experts,

Maybe somebody could help me?
A friend from Nantucket told me that he once read an interview by some famous movie critic (it might have been Leonard Maltin) with the white-haired British actor who played the dead body at Maryon Park in Greenwich, London, where the scenes have been filmed.
As the actor is not listed in the imdb Blow Up movie page, I was un-successfuil in my search.

Could somebody please give me a link to this interview?

Thanks,

Chrissie