The reason is that one of the zoo's minority shareholders is involved in another company where KPMG is the auditor.
"It is of the utmost importance that the external actor we commission to investigate this tragic event is independent from Parks and Resorts," says Furuviksparken CEO Sandra Wilke in the press release.
KPMG was hired on Wednesday after a "customary independent check".
It was on December 14 that five chimpanzees escaped from their enclosures at the zoo.
Four of them were shot dead, and it wasn't until December 17 that the zoo had the escaped animals back into their enclosures.
The three chimpanzees that were injured continue to get better, Furuvik states in the press release.