The Singapore Police Force said in a statement on 13 February that they were alerted to a suspected drowning incident near Kusu Island.
The drowning incident involved two men, of which one of the men is still missing.
The police were alerted to the incident on Sunday night at about 2.37pm, with a 28-year-old man being rescued and subsequently conveyed to the hospital.
The other man, a 24-year-old, is still missing and rescue efforts are currently underway to try and locate him.
A notice to boaters was put up by Singapore Marine Guide on their Facebook page, urging caution to boaters and advising them to steer clear of the waters between the Lazarus Island and Kusu Island.
They added that the Maritime and Port Authority of Singapore (MPA) and the Singapore Civil Defence Force (SCDF) were conducting operations in the waters.
The situation is still developing, stay tuned for more updates.