The boy, 14, got into difficulty while swimming with his aunt at an all-inclusive beach resort in the popular Antalya region on Sunday afternoon.
According to an onlooker, the hotel’s lifeguard was absent when the youngster, who was dragged unconscious from the pool by a barman, drowned.
A representative from the five-star-rated Liberty Lara hotel, where the teenager and the family were reportedly staying, said lifeguards arrived within less than a minute.
The onlooker said: “This happened at around 1pm and we heard the lifeguard had gone for his lunch.
“They tried very hard to revive the boy at the side of the pool but it was too late.
“It’s so sad, particularly when you consider they were there for such a happy reason.”
A hotel spokesman told The Sun: “It is with a heavy heart that one of our young guests sadly passed away yesterday while swimming with his aunt in our main pool.
“At this moment in time, our prayers and thoughts go out to the family and loved ones who are currently residing in our hotel.
“The sad, tragic loss of a young life is both devastating and shattering for the family, close relatives and loved ones.
“Out of respect for the family, we would like to refrain from making any comment about the incident until we receive the outcome of the autopsy.”
He added: “There are CCTV cameras located around the pool area which have been viewed by both the Liberty Lara management and the local police.
“Lifeguards were on the scene within 30 seconds.
“We have one additional lifeguard over the numbers required to ensure that the pools are not left unattended when a lifeguard takes a lunch break.”
The family’s trip was booked through holiday giant Tui.
A spokesman said: “We are aware of the tragic incident at the Liberty Lara in Turkey and our thoughts are with the family.
“Our team at the resort is currently supporting the family and we will continue to assist in whatever way we can.
“The safety and wellbeing of our customers is our primary concern and our dedicated resort team is supporting the authorities and hotel with their investigations.”