The dead bear was a “worldwide, emotional mascot,” the zoo's bear keeper Heiner Klös told public broadcaster RBB.
His mounted body will be displayed for educational purposes at Berlin's Museum of Natural History, “because there aren't that many polar bears any longer,” he said.
Klös also said he understood the opposition to preserving Knut in such a way, but insisted those against it were in the minority.
“Many think it's good,” he said, adding that other zoo favourites had also been stuffed after their deaths.
On Tuesday, a preliminary necropsy report revealed that the four-year-old polar bear likely died of an undiagnosed brain disorder, saying that “significant changes to the brain could be seen as the reason for the sudden death."
Knut was found lifeless in the pool in his enclosure on Saturday afternoon. An amateur video showing Knut's final moments shows the bear walking in repetitive circles, then having what appears to be a seizure before suddenly collapsing into the pool in his enclosure.
Further details of the necropsy are forthcoming, Klös said.
“Good examinations require good time and we want to tell the truth,” he told RBB.
Other than irregularities noted in Knut's brain, the rest of his organs were in “tip top” shape, ruling out a heart attack or poisoning, Klös said.
The bear's health was not in question before the episode, and Klös himself had checked in on Knut just an hour before he died.
Story continues below…
The problem was only “very suddenly apparent,” he said. “Then it was too late.”
Knut shot to fame as a cuddly cub after being abandoned by his mother and reared by hand.
Devastated fans have been leaving flower bouquets, written tributes and photos of Knut at his former den at the zoo, while an online condolence book has drawn more than 4,000 messages.