Det Supt O’Meagher said it was unknown at this stage if the pair were in a relationship.
“The investigating police have spoken to the family of the deceased and our thoughts are with them at this very difficult time,” he said.
Charges are yet to be laid as police undertake a homicide investigation.
The zoo has been closed and it is not known when it will reopen, but police do not believe there is an ongoing threat to the public.
Acting Opposition Leader Sussan Ley described the death as “another horrific tragedy.
“As a woman I am angry, and I am shattered,” she said.
“More than 60 women have already been killed by someone they know this year. Enough.
“This is a national crisis. We must stop this violence.”