Three puppies found dead in Sheung Shui are suspected to have been poisoned, police said on Thursday.

Officers said they had opened an animal cruelty investigation following the discovery of the dogs' bodies near a warehouse in Lin Tong Mei.

Vomit was found next to the puppies, who were around two months old, police said.

Another dog was found alive and was handed over to the Society for the Prevention of Cruelty to Animals.

No arrests had been made, police said.

District councillor Corey Lau said he joined animal rescue volunteers in saving two injured dogs from the same site late last month, and they had also spotted several puppies there.

"We had to settle the two rescued dogs and then we planned to return to the place and save the puppies. However, when we returned to the scene, we found that three of the puppies had already died and one was barely alive inside the warehouse," he told RTHK.

Lau also said he had come across more than 50 cases of dog poisonings in the past three months, many of them in North District and Yuen Long.