A "witness" to the death scene was Luis Lupi, who took the black and white photos. He wrote on 24 March 1946 to Robert Bunnell, of the Associated Press in London, the following description:
The giant of Chess – dead, resembled a fallen oak tree. In his face he kept an expression of deep thought.
24 March was the same day that Alekhine's corpse was discovered in the hotel room at about 11 AM. Lupi had to have had the film developed immediately that day (a Sunday?).

Yes, def murdered. Also, a few of the recent GM deaths in Russia have been murders as well. When the Russian Federation reports a death from natural causes, don't believe it. Too coincidental so many of these guys "jumped" to their death.