Ms Ng, well known among many expats in Phuket for her charity work, disappeared while taking a jet-ski ride off Patong Beach late last month.
A boat captain operating nearby reported that at around 9:40am, he saw the tourist remove her life jacket and jump into the water about one kilometre from Patong Beach on Feb 27.
Before that, Ms Ng was last seen renting a jet-ski from the southern end of Patong Beach at about 1pm.
Rescue workers from the Kusoldharm Phuket Foundation, along with dive teams and lifeguards, mobilised to assist in the search for Ms Ng.
However, they were unable to find her. After three days the search was reduced to an appeal to the public for help.
The body found between Koh Bon and Koh Racha yesterday morning, due to its condition, was initially thought to be a man. The body was brought ashore at Chalong Pier.
Now police are working on the presumption that the body is that of Ms Ng.
Pol Col Rungrit Rattanaphakdee, Superintendent of Chalong Police Station, which is responsible for the marine area where the body was found, told The Phuket News that the clothes that the body was found in matched the description of those Ms Ng was last seen wearing.
Pol Col Rungrit confirmed that the information had been handed over to the Patong Police, who are responsible for the case.
Pol Lt Col Suchart Chumphusang, head of Investigation, at Patong Police Station, told The Phuket News that he was confident the body had been correctly identified.
The Phuket News was also told that identification of tattoos had also contributed to the confidence that Ms Ng’s body had been found.
Regardless, Pol Lt Col Suchart said that a DNA test had been requested to confirm the identification.