Last year, Toronto City Council, the owner of the zoo, voted to send three African elephants to the Performing Animal Welfare Society's 2,300-acre facility in California, but zoo board officials have resisted at every turn, the Toronto Star reported.
This week, the zoo requested PAWS provide a tuberculosis report on every animal that died at the facility, as well as necropsy reports for all deaths in the past five years.
PAWS co-director Ed Stewart told the Star that wasn't going to happen.
"No request like that has ever been made of us -- or anyone else," he said. "It's above and beyond ridiculous, and it's totally insulting."
Toronto Zoo officials say the PAWS facility isn't accredited by the Association of Zoos and Aquariums, although PAWS isn't considered a zoo, but rather a rescue facility.
Because of the Toronto Zoo's resistance to moving the elephants, the AZA revoked its accreditation in April until March 2013.
Television celebrity and longtime animal rights activist Bob Barker has volunteered to pay the cost of shipping Toronto's elephants to California, although the safest and most cost-efficient methods haven't been determined.