The following is a summary
of phone interview with Anakundubhi das in October 1999:
This kaviraja was very old, ninety something at the time, so Prabhupada sent a car for him. Pallika was in charge of the schedule of eating that the kaviraja had given; Prabhupada was supposed to eat some things and not others. They started cooking for him with no spices; I think it was Harikesh who was doing the cooking. That day one devotee asked Prabhupada how the prasadam was and he scowled and said, "Dishwater."
The day after the kaviraja came, Prabhupada was sitting on the veranda in the afternoon and I brought him his dub. He took it and just as he was about to start drinking Pallika ran up and said, "Prabhupada, you can't drink that!" Prabhupada said, "I will do whatever I like, I always have since I was a child." And that was the end of the diet, after that I think Pallika started cooking for him again with all the normal spicing.
Another time I remember him mentioning about his kidney problems. He was requesting shukta and was saying how the bitterness of the karella was medicinal for his kidneys. He also mentioned that the mustard oil massage also helped.
I don't have contact with any of the people involved in this poison conspiracy theory. In fact I only heard about it recently when Rama Prasad Prabhu mentioned it, so I am not in any camp. However, my opinion is that the theory is untrue. I know that Prabhupada was sick because of his kidney problem, he told me so himself.