A man who apparently put a dog in a washing machine and posted photographs on Facebook showing it struggling in the water has sparked a police investigation into suspected animal cruelty. The pictures of the small white dog submerged in water and being spun round in the machine appeared on the Facebook page of a user going by the name of Jacky Lo. The photographs were accompanied by a smiley icon. In response to a comment underneath asking if the dog was dead, Lo answers: "Yes! Do you want to see it!" The post has sparked outrage online, with thousands sharing the photographs and calling for police to investigate. It is not yet known if police have tracked down the man involved. The Hong Kong Society for the Prevention of Cruelty to Animals called the incident "truly horrific". It is the second large-scale outpouring of anger and grief over the death of a dog within the last month. Two weeks ago, hundreds of people held a rally in protest at the MTR's failure to rescue a dog that was hit by a train after it strayed onto rail tracks at Fanling. The pictures of the dog in the washer caught widespread attention this week after being posted on August 12 by "Lo", who reportedly lives in Tuen Mun. Although it has not been confirmed whether the Facebook identity is genuine, the photographs appear to be real. They show the dog, believed to be a white West Highland terrier, clinging to the side of the top-loading machine as the water gushes in. Following shots show the dog submerged. One picture shows the dog soaking wet and sitting on a tiled floor looking up at the photographer. Lo comments on the photo in Chinese: "A super quick way to wash a dog: soak, clean, and dry. All done. Clean and quick!" He then adds a smiley icon and the words "feeling content" in English. On Friday, the SPCA posted a statement on its Facebook page alongside a screenshot of the post. "The SPCA is extremely concerned about the incident. We have already referred it to the police and we will continue to assist investigations," it said. Police confirmed that officers from Tuen Mun were investigating following a complaint. SPCA spokeswoman Rebecca Ngan said people began telephoning and emailing the SPCA after the pictures started circulating on Thursday afternoon. "We received about 50 emails overnight from people who were very concerned," she said. "Obviously, even if the dog is not dead, to put a dog in a washing machine would still be cruelty." By yesterday afternoon the photos had gone viral, shared by thousands on Facebook who mostly expressed horror and disgust and called Lo "sick" and "scum". An online petition calling for him to be punished has clocked up more than 4,000 signatures. Animal cruelty carries a maximum sentence of three years in prison and a HK$200,000 fine.