Police are considering a complaint against the Scottish SPCA after the animal charity killed a snake it believed was dangerous by putting it in a freezer.

The suspected green mamba was found on a ship that arrived in Aberdeen from Africa last month.

It was taken to the Scottish SPCA's Aberdeenshire wildlife centre, where it was destroyed when vets were unable to find a local keeper willing to take the reptile.

The snake was later identified as a harmless green tree snake.

Police Scotland said: "We have received a complaint and it is under consideration."

Scottish SPCA chief superintendent Mike Flynn said: "We could not keep the snake in our centre due to severe health and safety concerns, as the closest anti-venom is held in Bedford.

"Green mambas also require a Dangerous Wild Animal Licence, which the society does not have.

"The safety of our staff and the public is paramount and as such the snake was placed in a freezer, where it passed away."

He added: "The Scottish SPCA is proud of its policy not put healthy animals to sleep.

"Animals are only put to sleep on veterinary advice if they are too ill or too aggressive to be rehomed, or where we are legally required to do so.

"The decision to euthanise the snake was not taken lightly. Unfortunately, the snake has since been identified as a harmless green tree snake.

"This has been an honest mistake on the society's part as we genuinely believed this was an extremely deadly snake."

Experts are divided over whether or not freezing is a humane way to kill reptiles, with opponents claiming the process causes painful ice crystals to form on the animal's skin.