The father-of-two was found unresponsive in his suite by hotel staff in Kampala on Friday (17Feb12) and he was later pronounced dead at a nearby hospital. A cause of death has yet to be determined but officals have not yet ruled out foul play.
Rice's assistant, who local reports have identified as Catherine Fuller, was also found unconscious in the room; she is currently listed in critical condition.
Sally Blackman, Rice's widow, tells Fox News, "They were not attacked but (evidence) points towards being poisoned. (At) this stage it is quite difficult to give you any firm reports as the incident is currently under investigation by the Uganda police."
Rice worked on a number of hit reality shows including The Amazing Race, Animal Planet's Whale Wars and a South African version of The Biggest Loser.
A number of stars have since spoken out to express their grief over Rice's sudden passing, among them famous explorer and TV personality Josh Gates.
In a post on Twitter.com, he writes, "Floored by the loss of my dear friend & fellow adventurer, Jeff Rice. You were, quite simply, the real deal. I'll never forget you... I can't believe you're gone, buddy."