Four of the five rare monkeys stolen during an overnight break-in at Blackpool Zoo have been found alive and well, Lancashire Police have confirmed.
The monkeys were discovered in a cardboard box in a doorstep in Brighouse, West Yorkshire on Friday night after thieves broke into their enclosure and stole the animals.
However, the baby monkey is still missing and the Zoo said it is "saddened" the cotton-top tamarin has not been found.
Two female and one baby Cotton-top Tamarins, which are a critically endangered species, and two male Emperor Tamarins were reported missing by the zoo on Friday morning.
Their details have been circulated to all ports and airports by police concerned the animals were targeted specifically.
Lancashire Constabulary's Andy McWilliam said officers were "making inquiries across Europe" because there was "definitely a market for the monkeys".
Keepers issued an appeal for the safe return of the animals which need specialist care in order to survive.
"All the animals were born here at Blackpool Zoo and are part of our zoo family, so I would like to urge anyone with any information to contact the police," the zoo's director Darren Webster said earlier this week.