The suspicious powder discovered in an envelope in Tauranga City Council's mailroom last Friday was not hazardous.
Susan Jamieson, general manager of people and engagement at the council, said the powder had been identified as a "non-hazardous food-grade product".
A police spokeswoman said inquiries into the incident were ongoing and no arrests had been made.
Mayor Greg Brownless said he was pleased to learn the powder had not posed a threat to staff.
Nonetheless, he believed the intent of the delivery was not so innocent.