Police have asked the public to be vigilant after two cats were poisoned in Rushden.
The incidents happened between Wednesday, January 10, and Tuesday, February 13, in the Park Avenue area of the town.
A cat owner had two cats die which were confirmed by a vet to have been the result of poisoning.
A police spokesman said the incidents are not believed to be linked to other cat deaths in the county, which they have arrested a 31-year-old man on suspicion of.
The spokesman said: “We are also not linking these incidents to the ones that have taken place in London.”
Anyone with information or reports of suspicious activity in the area are asked to call police on 101 or Crimestoppers anonymously on 0800 555111.