Capt Channarong Prakongkue of the Karon Police was notified of the incident and reported arriving at the scene with rescue workers and fellow police to find the body of the woman on the ground.
The woman was identified as Kristina Resetnikova.
Capt Channarong declined to identify the hotel where the incident occurred.
Capt Channarong noted that Ms Resetnikova had arrived in Thailand with her husband and son on Dec 24 to celebrate Christmas and the New Year.
The family of three were to depart Thailand next Tuesday (Jan 8), he added.
Karon Police Chief Col Prasarn Hankotha told The Phuket News this morning, “The husband (Andrejs Resetnikovs) came back to the hotel after celebrating the New Year at about 3:30am.
The husband was sitting in front of the hotel before going up to their room, he added.
“He saw her climb over the balcony rail and was walking on the outside of the balcony when she slipped and fell.
“The husband believes it was accident,” Col Prasarn said.
The husband’s description of events was corroborated by CCTV footage from the area, he noted.
Col Prasarn said that Ms Resetnikova had been drinking some alcohol, but believes that she was not overly drunk at the time of the accident.
“We have no idea what would have prompted her to do this,” Col Prasarn said.
The baby, a 19-month-old boy named Marats, was still in the room, he added.
“We could see that the baby was being well cared for. He was healthy and even well dressed,” he said.
There were no signs of a fight or anything unusual in the room, Col Prasarn added.
“Everything seems to have been normal, but we are still continuing our investigation,” he said.
Additional reporting Tanyaluk Sakoot