Mr Walker's Last Mile is an article by Vir Sanghvi. In it, he recollects a meeting with Lee Falk in Mumbai, India in 1980.
It was published on 21 March 1999 by The Telegraph (an Indian newspaper).
The author typically writes critical articles on Indian politicians. This article should be read keeping that in mind. Also note that there is an error in the article: it is mentioned that Kit was the Phantom's adopted son but this is incorrect as the adopted boy was Rex.