A second swimmer has died after taking part in the Hong Kong Harbour Race.
An event spokesman said a 59-year-old woman named Cheung died on Wednesday, having been pulled from the water on Sunday and taken to intensive care.
A man died during Sunday's event. Both were in the 'leisure' category for slower swimmers.
World aquatics governing body Fina announced a review of the race and other open-water events globally following Sunday's death.
Three thousand swimmers registered for the 1.5km race, which resumed in 2011 after a 30-year break because of fears of pollution levels in the water.
Hong Kong is one of the world's busiest ports, used by more than 400,000 vessels every year.