His mauled body was discovered Sunday by a visitor to the zoo in this central Southern African city, prompting initial confusion as to how the man ended up in the enclosure.
Police said Wednesday the man and an accomplice had robbed a couple at knifepoint early Sunday. Security guards gave chase and one of the suspects jumped over the perimeter fence. He then apparently ran to the tiger's den in the middle of the zoo.
"What exactly happened we don't know and we won't ever know because the only person who could tell us is dead," police spokeswoman Else Gerber said.
She said there was an empty can of beer near the corpse and that the autopsy would reveal whether the man was intoxicated at the time.
Zoo officials have said the Bengal tigers will not be destroyed because they were blameless. The tigers had been fed on Saturday and so did not eat the man because they were not hungry, according to media reports.