The zoo is to maintain its policy of allowing animals to roam freely

Trinity parishioners and visitors to the zoo had been asked to help look for the silver-coloured marmosets, which had roamed outside their fences.

One marmoset, which was alive, and the bodies of the other two were found in dense woodland near Victoria Village.

It is thought they died of the cold, but the zoo is to carry out post-mortem examinations on the dead animals.

'Rare incident'

The zoo said that, despite the deaths of the creatures, they would keep their policy of letting animals roam freely around the zoo.

Don Wormell, from the zoo's mammals department, said it was amazing that one of the marmosets had survived.

He said the zoo would continue to train animals to cope in the wild.

"In many ways the fact that one survived goes to show how wild these animals really are," he said.

"We have been allowing the animals to roam free for 15 years now and this is a very, very rare incident."