Authorities in Indiana’s Spencer County have confirmed a report that shelter animals were euthanized on two separate occasions by freezing them.

The total number of animals killed in this manner is unknown. A handful of witnesses have spoken with the Spencer County Sheriff’s Office that in one of the instances, four kittens were frozen to death. The Indiana State Police are expected to take over the investigation by the end of August.

The matter first came to light after an employee refused an alleged order to put a kitten, and then another cat, in a freezer.

The American Veterinary Medical Association has deemed hypothermia as an unacceptable and inhumane mode of euthanasia.