A spider monkey that died following a break-in at the Greater Vancouver Zoo suffered a fracture to his skull, according to a preliminary necropsy.

Jody Henderson, a spokesperson for the zoo, said the results showed the monkey suffered internal hemorrhaging on the right side of his skull.

The monkey, called Jocko, was discovered dead on Wednesday morning by zoo keeper Cindy Hulst.

The culprits, who apparently used bolt cutters to break through the cage, also kidnapped Jocko's mate, Mia.

Henderson said the cutters may have been used to kill Jocko.

"Or he could have been thrown against the tree or tree house that's inside the enclosure," she told CTV's Canada AM on Thursday.

Henderson said she can't think of any motivation for the break-in.

"It just doesn't make sense," she said.

Meanwhile, zoo officials are hoping to get Mia back in their custody.

"The average person doesn't have a clue how to take care of an exotic monkey," said Henderson.

She also said Mia could be a danger to the public since she is traumatized and will likely be in a fighting mood.

Cpl. Peter Thiessen, a spokesperson for Langley RCMP, said the monkeys are valued at $5,000 each.

"Certainly it's not so much their value but clearly they're members of the family here," said Thiessen.

He said perhaps the thief wanted to sell the monkey on the black market or keep it as a personal pet.

Jocko and Mia have been residents at the zoo for about 15 years.

With files from The Canadian Press