The pair went in to sort through Mr Butler's belongings and pick up a dog when a man claiming to be the landlord arrived, and he threatened them with trespass about their right to be there, Ms Butler said.
They left and made a complaint to police.
During that meeting Mr Andrews claimed to be friends with the landlord, according to Ms Butler, who said he phoned the man and released private information about Mr Butler's will.
Ms Butler also complained that Mr Andrews did not document her complaint, allowed the man to act as the landlord without checking that it was actually the man's sister who owned the house, and later tried to get Ms Butler to pay unpaid rent and dissuade her from going to the Tenancy Tribunal where it was revealed no rent was owed. "It was just bullying tactics. It could have easily turned into something more serious if I'd paid money over. But I just basically stuck to my guns and said 'no'."
The tribunal granted access to Ms Butler six months after her father died but she said by then some of her father's possessions were missing.
Bay of Plenty police professional standards manager Inspector Anna Jackson, who investigated the complaints, told Ms Butler in a letter she upheld the complaints about breach of privacy, coercion and conflict of interest.
Ms Jackson said when questioned Mr Andrews explained he was trying to impress on the man that Ms Butler was next of kin and wanted to settle her father's affairs.
The inspector did not consider Mr Andrews' information sharing a severe breach of privacy but said it was nonetheless unacceptable.
Mr Andrews told Ms Jackson he did not recall insisting Ms Butler pay owed rent and was more worried about Ms Butler appearing to only want to take some property and leave the rest.
Ms Jackson said it was clear from Mr Andrews' language and demeanour when dealing with the man that the pair were friends and he did not appear to be acting neutrally.
Ms Butler said Mr Andrews should have handed the case over to someone else.
"It's that small-town police culture where they think they can manage their conflicts of interest without any accountability to the public. It's just absolutely unacceptable."