After retiring three weeks ago she moved to Gisborne to live with Rota, for what police said was supposed to be a "happy retirement".
"Sadly, that came to an end on Friday when Dakota became very unwell, was taken to the vets and died," the Facebook post said.
"She had been diagnosed with Addison's disease several years ago but this was managed with medication and it didn't stop her from leading a very active operational patrol dog life.
"Whether her condition shortened her retirement is not yet clear, but we do know she enjoyed being reunited with her old partner."
Rota said he was gutted she was gone.
"She loved every minute being at home, her daily walks along the beach, and hanging out with us. We'll all miss her."
The pair finished seventh in the 2018 Police Dog National Championships, and Dakota tracked and made hundreds of catches over the years.
She also wowed crowds at the Wings Over Wairarapa when she was winched from a RNZAF NH90 helicopter and was used to travelling by boat as part of her training in responding to armed incidents.