Last night (August 26), police had confirmed that they were looking into reports that a "large cat" had been spotted in fields around Earl's Hall Drive at around 7pm, and advised residents to stay in their homes.
Today, however, Sky News reports that officers have effectively given up the operation after a near-24 hour search for the animal provided no evidence.
Police helicopters, armed officers and workers from Colchester Zoo armed with tranquilizer guns looked for pawprints and droppings last night, but were unable to find any.
Witnesses had initially reported seeing a lioness prowling up and down a hedgerow before it was disturbed by a farmer and ran off.
Wildlife experts have subsequently suggested that the sighting may have been of a puma lioness, which has allegedly been sighted in Essex a number of times previously.
An Essex police spokesman said today: "We believe what was seen on Sunday evening was either a large domestic cat or a wild cat.
"Extensive searches have been carried out, areas examined and witnesses spoken to; yet nothing has been found to suggest that a lion was in the area."
The Essex lion has proved a big hit on the internet, with dozens of jokes and spoof photographs appearing within hours of the news breaking, and spoof Twitter account @essexlion has attracted over 37,000 followers since yesterday evening.
After the news broke, the account tweeted: "THE ROZZERS HAVE GIVEN UP! CHAAAAAMPIOOON! GOING FOR A VICTORY KEBAB. OR THE BLOKE BEHIND THE COUNTER, WHATEVS (sic)."