Samba escaped from the zoo on 17 March, less than 24 hours after arriving.
She managed to break free from a temporary enclosure with Tango, who was swiftly recaptured.
Samba, described as the more adventurous of the two, has remained at large ever since.
Over the past four months, the young capybara has been spotted in a number of locations, including near a pub and basking on a riverbank.
On 6 July, search teams were sent to the Brambridge area after a fisherman reported a credible sighting at the end of June.
Despite extensive efforts involving thermal-imaging drones and a specialist sniffer dog, Samba has so far evaded capture.