Concern was raised today after a number of suspicious packages containing white powder were delivered by post to five public buildings in Kettering.
They appeared at the Kettering sorting office before arriving at the buildings, which included two banks and a private business.
However, after testing the susbstance, Northamptonshire Police confirmed that it was, in fact, crushed paracetamol.
A police spokesman said: “Extensive tests revealed the substance to be crushed paracetamol, which was harmless.
“We would urge anyone who finds anything suspicious in the post to contact the police in order for properly trained officers to deal safely with any substance.”