Was Rafsanjani Murdered?

Maybe. But there's a good chance we may never know for sure:

It is not beyond the realm of the impossible that an overweight, out-of-shape, 82-year-old would have a heart attack and die in the hospital. But, sometimes the conspiracies which surround such occurrences provide significant insight into the society in which such events occur. 

According to political activists Mitra Yekta and Goli Ebrahimi, Rafsanjani’s son Mehdi Hashemi addressed the crowd gathered in front of the hospital where Rafsanjani died. He kept screaming “They killed my father” and then explained, “My father had a meeting with a group of IRGC commanders and drank a cup of tea or something that gave him instant heart attack.” He asked for an autopsy but Supreme Leader Ali Khamenei vetoed the request. Supposedly, the funeral for Rafsanjani will be in Mashhad instead of the capital Tehran in order avoid any chance for protests in the Iranian capital.