Heather Roach, deputy chief constable said the investigation culminated in a decision being made that Falco should be euthanised and this has now been carried out.
She said: "This was an incredibly tough decision to make given the nature of the circumstances and the fact that our dog handlers care a great deal about their dogs, as we do as a force.
"As difficult as it was to take this action, which was carried out with very heavy hearts, it was decided that the best course was to euthanise Falco to ensure this type of incident never happens again.
"An IPCC investigation is still underway so we are limited in what we can say in relation to the exact circumstances until those enquiries have been completed."Professional Standards Department must be wishing it had this sort of power to act in other cases...