More than one million of the phones have already been sold in 10 countries since its launch two weeks ago.
Samsung has said it is suspending sales of its Galaxy Note 7 smartphones after finding some of the batteries exploded.
Some buyers reported their phones caught fire or exploded while they were charging, and Samsung said it had confirmed 35 such cases, caused by faulty batteries.
Since late last month, several users have posted photos and videos on social media showing the charred Note 7 with part of its 5.7-inch touchscreen burnt and melted, saying it suddenly caught fire.
Samsung has confirmed 35 such cases in South Korea and overseas.
The president of the firm's mobile business, Koh Dong-jin, said an investigation by the company found a battery cell made by one of its two battery suppliers caused the phone to catch fire.
He refused to name the battery supplier.
He said: "We have received several reports of battery explosion on the Note 7 that was officially launched on 19 August, and it has been confirmed that it was a battery cell problem."
He added he was "deeply sorry" over the incident and customers who already bought Note 7s will be able to swap them for new smartphones, regardless of the purchasing date.
Samsung Halts Galaxy Note 7 Sales Following Battery Explosions