An endangered monkey stolen from Blackpool Zoo along with her baby and later abandoned left keepers stunned to discover she was pregnant at the time.
Staff were left fearing the worst when five monkeys, including cotton-top tamarin Mamma, were taken in a well planned raid.
But they are now celebrating after she gave birth to healthy twins.
Mamma, who is on the critically endangered list, was one of four monkeys found and returned just days after police launched an international investigation into the theft.
The fifth monkey, her baby, was never found.
After beating the odds by surviving the ordeal and making it home with a clean bill of health, Mamma raised eyebrows again by giving birth to the twins.
Staff at the zoo say mother and babies are doing well despite her traumatic experience.
Charlotte Pennie, senior primate keeper, said: “Keepers at Blackpool Zoo were devastated earlier this year when five of our monkeys were stolen, as every single animal we have here is considered a member of our zoo family.
“We worked very closely with Lancashire Police and following huge media interest four of the five were found days later.
“The two new babies, who are yet to be sexed and named, are doing extremely well and we are delighted. The pair are also vital for the international breeding programme, so it is great news all round.”
Three critically endangered cotton-top tamarins, including Mamma and her baby, and two male emperor tamarins were stolen overnight on April 29 when thieves cut through a fence.
They then evaded security to unscrew locks on two cages, sneaking the primates out without anyone noticing.
But the monkeys hit local and national headlines, prompting the thieves to abandon them in Yorkshire, when police announced they had every port and airport in the country on the lookout for the animals and were making inquiries with police forces across Europe.
The four adults were returned to the zoo safe and well just days after being reported missing.