The buyer's real estate agent, Ivonne Bonner, says it's no surprise.
Assistant Commissioner of Police Crime Vincent Wong Fook-chuen said that 19 officers from the Commercial Crime Bureau were investigating.
Although the original post was deleted after a few hours, the image did the rounds at other major forums in Hong Kong such as and.
But Lam was also known for her erratic behaviour, which some speculate was due to her mental health issues.
Director Au Cheuk Man was furious about the leak and told the Hong Kong media that he vowed to find the culprit, which could also make for an interesting film plot.