Twycross Zoo was temporarily closed on Thursday after an incident involving a group of chimpanzees which were being moved within the Leicestershire grounds.
Police were called to the zoo at 9.35am after the transferral of eight primates from one enclosure to another went awry.
A Leicestershire Police spokesman told Huffington Post UK: "A number of chimpanzees got into a part of the zoo they were not supposed to be in", resulting in officers being contacted.
She added: "They don't appear to have actually physically escaped. All animals were contained and there was no immediate danger to members of the public."
It later emerged the chimps had been lured back to their rightful area with ice cream and fizzy drinks.
The zoo has since been reopened.
The incident resulted in mass speculation on Twitter as to whether or what animals were now prowling the East Midlands countryside.
Primarily known for its primates, the zoo is also home to leopards, elephants and camels.
Animal on loose at Twycross Zoo.
Guessing monkey, could be anything.
Armed police presence suggests not a penguin...— Andy Jones (@Andyjoneswrites) August 1, 2013
Are we sure this animal 'incident' at Twycross Zoo isn't the real-life start of the Planet of the Apes?— Joel Taylor (@JoelTaylorMetro) August 1, 2013