Thieves have stolen two monkeys from an enclosure at a wildlife park, police said today.
The female squirrel monkeys were snatched after raiders broke into the Cotswold Wildlife Park, near Burford, Oxfordshire, last night.
Staff discovered the enclosure had been entered and the animals were missing at 7am this morning.
Pc Simon Towers, Thames Valley Police wildlife officer, said: "This is a highly unusual crime. There has not been a similar theft of a monkey nationally since 2006.
"We are very concerned about their welfare - they have a highly specialised diet and would be severely traumatised by the experience so we need to recover them as soon as possible.
"If anyone saw any suspicious vehicles or people in the vicinity of the park, which is accessed from the A361 south of Burford, then please let us know.
"I would also like to advise the public that, while they might be cute-looking animals, they are wild, may be frightened and could easily bite someone.
"If you do see them, do not attempt to approach them but contact the police immediately or the park directly."
The stolen monkeys were called Stripe, who in her 20s was the oldest in the group at the park, and Deana, who was in her teens.
Curator Jamie Craig said the thieves cut through a number of fences and then kicked down a heavy door to gain entry to the area where the animals were sleeping.
He said: "They were pretty persistent and pretty determined. I don't believe this was done opportunistically."
Mr Craig said staff at the park were trying to reintroduce a young monkey which had been rejected by its mother back into the group.
He added: "People may have seen this young animal and thought it would make a good pet, not realising that it is taken home by the keeper every night.
"Once they had broken in they may have grabbed the older two monkeys because they were slower in getting away than the others."
Mr Craig said not only would the stolen monkeys be traumatised by their ordeal but the others left behind have also been badly affected.
Police scenes of crime officers were examining the enclosure and that the park has stepped up security at the site, he said.
"The staff are upset and angry - they just don't understand these people.
"We are all thinking 'Where are these animals now? Where are they living? What are they going through?'
"It is devastating for everyone. When you have a group of monkeys like this it is like ripping two family members away.
"My fear is that the two stolen will end up in a bird cage in someone's lounge.
"We just want these monkeys back safe and sound as soon as possible," he said.