Officers in the government flying services and firemen searched for a person suspected to have drowned off Yung Shue O in Sai Kung in the New Territories on Thursday, but no body was found.
At 10am a foreign domestic worker at a village house in Sai Keng in Sai Kung district saw a person waving their hands in the water off Yung Shue O. The maid told her female employer, Wen Wei Pao reported.
The domestic worker said the person wore a black top and appeared to be drowning and wanting to be rescued.
A fireboat and a police vessel went to the scene but could not find the person, Apple Daily reported.
At 1:40pm government flying service officers and a diving team from the fire department were deployed for the search, but they were also unable to find any person or body in the water before nightfall.
Police said they had received no reports of people missing but they were not fully sure if it was a false alarm.