Six alpacas have been shot dead on a rural Queensland property close to the border, eight months after seven other alpacas were killed with a similar weapon less than 15 kilometres away.

In the latest incident, police were called to a Glen Aplin property, 155 kilometres south of Toowoomba, on Saturday after the alpacas' owner found five dead and one critically injured in their paddock.

The surviving animal from the Mount Stirling Road property was euthanised by a vet, who concluded the alpacas had been shot with a small calibre gun on either Wednesday or Thursday.

Stanthorpe Police Senior Constable Jim Ellis said the animals would have been defenceless and it was hard to comprehend the senseless violence.

“Disturbingly this is the second incident of shooting deaths involving alpacas on rural properties with seven killed at Lyra last September," he said.