The BC SPCA says its investigation into the death of a giraffe at the Greater Vancouver Zoo is being hampered because workers refuse to share key information.

SPCA spokeswoman Lorie Chortyk said her organization has been forced to seek a warrant to obtain documents the zoo could simply hand over willingly.

“It’s very frustrating for us because as a non-profit society we’re entirely donor-funded, and that includes our cruelty investigations,” Chortyk said. “We’re now having to staff time to take legal steps to get information.”

The SPCA said the zoo is refusing to share records relating to the animal’s care, diet and necropsy results.

The 12-year-old giraffe Jafari was found collapsed and lifeless in his heated barn at around 7:30 a.m. Sunday, marking the third giraffe to perish at the zoo in a year.

Veterinarian Bruce Burton, who cared for Jafari for most of the animal’s life, was called to conduct a necropsy Sunday morning.

He said Jafari was healthy, with a good layer of insulating fat to keep him warm, and there were no signs of physical trauma.

“There was a few changes on the valves of the heart, but probably not enough to account for any kind of… fatal incident. But there could be some minor degree of pathology that was there,” Burton said.

Tissue samples from the animal are also being tested, and the results are still pending.

One surviving giraffe remains at the zoo.

The Vancouver Human Society says giraffes in captivity require a very special diet, particularly in colder climates, and argues the zoo should stop keeping them altogether.

But zoo general manager Jody Henderson insists the animals’ diet did not contribute to their passing.

“We have a giraffe diet that is specific for northern climates. We’ve had the diet for a number of years. We know all this information,” she told CTV News on Monday.

Jafari’s three-year-old offspring Amryn died on Nov. 14, 2011, and was followed six days later by the calf’s 23-year-old mother Eleah.

Both deaths were considered premature, as giraffes are expected to live around 28 years in captivity, but a conclusive cause was never determined.

With a report from CTV British Columbia’s Peter Grainger