Five wolves managed to escape from Colchester Zoo after the perimeter fence was damaged.
Two of the wolves were shot and killed, one was recaptured while the other returned voluntarily.
Essex Police are searching for the remaining wolf who is thought to be sheltering in thick undergrowth.
A police helicopter has been deployed to assist with the search.
For more on this story visit ITV Anglia
More top news
A Branislav Ivanovic header in extra-time ensured that Chelsea are through to the Capital One Cup Final after beating Liverpool
Scientists have discovered the oldest known earth-size planets discovered which they say raises the prospect of 'ancient life'.
Auschwitz survivor Alina Dabrowska was a victim of the cruel experiments of Nazi doctor Josef Mengele, known as "the Angel of Death."