The SNP's Carolle Ralph stepped down in December after spending six months representing Lossiemouth's Heldon and Laich ward, following what had been described as a "vicious, bullying and personal campaign of intimidation".
Ms Ralph had been one of two SNP candidates in the ward, which includes Lossiemouth. While she was elected, the other SNP candidate, David Stewart, was the most surprising casualty in Moray.
Mr Stewart resigned from the party, but there is no suggestion he was responsible for smearing Ms Ralph. It has now emerged police have questioned his wife Joan Stewart.
Police confirmed their inquiries into the sending of a series of letters had concluded and report was being prepared for the procurator-fiscal.