Phuket News reports that the events took place after 20-year-old Wuttisan “Tei” Wongtalay threatened to kill his girlfriend, 21-year-old Jiranuch “Bew” Trirat. She ran away, leaving their baby Beta with him.
Ms Jiranuch told police that he had found her phone, and accused her of cheating on him.
“At 3am yesterday he checked my phone and threatened to kill me,” she said.
“I was very afraid and ran away from the house and left Beta with him. I returned home late in the afternoon and they were not there. I called him to bring Beta back to the house, but I could not get in touch with him."
She added that she later saw a video posted to his Facebook page which showed him tying a rope around their daughter's neck and hanging her out the window.
“The video clip, which is about four minutes long, was posted at 5:45pm yesterday,” said Lt Col Sanit Nookhong from the Thalang Police.
“In the video, Wuttisan shows a bottle of liquid, which we later confirmed was kratom drink. He gives the girl, Beta, a drink and has a drink too. After that he ties a rope around the girl’s neck and lowers her down.
“You can hear the girl crying and finally the crying stops. Then he pulls her up onto the roof top and unties the rope from her neck,” he said.
Facebook is currently under pressure to prevent distressing content from being uploaded so easily. They have also faced criticism for leaving the video up for so long - it was only removed after 24 hours.
A statement from Facebook about the incident described the events as "appalling".
"Our hearts go out to the family of the victim," it said.
"There is absolutely no place for content of this kind on Facebook and it has now been removed."
This article first published on Marie Claire.