A 31-year-old Chinese national died on Tuesday afternoon after he was found unconscious in a pool at M Hotel in Anson Road.
He was taken to Singapore General Hospital, but did not survive.
The police were alerted at about 4.15pm that day.
A hotel spokesman told The Straits Times that hotel staff were immediately alerted to the incident and administered emergency aid before a team from the Singapore Civil Defence Force arrived.
The Chinese Embassy has been notified of his death, the spokesman added.
The hotel is in touch with the man's next of kin and is "providing support to the family during this difficult time".
A check by The Straits Times yesterday found the pool area closed.
Police investigations are ongoing.
The pool will reopen to guests today, the hotel spokesman said.