'Chugger' was given alongside rare bravery awards at an event on Friday night.
The police wrapped up its search, but the family and the public are still on the lookout.
One dissenting councillor said it's a mistake not to think long-term about what will be a 100-year asset.
The business owner told Newshub he knows the tactic adds fuel to the fire.
Det Snr Srgt Damon Wells said they have "exhausted all viable search area options".
The public is being asked to check their sections, including any sheds, in case Warrington has sought shelter.
The message contained an abusive slur which called for the worker to go back to his country.
The enclosure's been empty since 2016 after the previous otters died of old age.
Police have received three separate reports relating to the Christchurch mosque in the past fortnight.