Police confirmed that the woman, named as Ms Htike Darlee, was found dead in her cell at about 5:03am.
Pol Lt Col Weerayut Thansirisukvorakul, Investigator at Phuket City Police, said he was notified of the death shortly before 8am. A forensic doctor, the district chief and a Phuket Provincial Prosecutor were called to witness the scene and the post-mortem examination.
CCTV footage from inside the cell showed Ms Darlee tying her trousers to the bars and hanging herself, police said.
A CCTV image revealed to The Phuket News showed Ms Htike Darlee hanged from the detention cell bars.
According to the report by Phuket City Police, Ms Darlee had been released from Phuket Provincial Prison on Aug 15. She was collected by Thalang Police officers and later transferred to Patong Police Station, which was handling her case.
At 2:30pm yesterday (Aug 21), she was moved to Phuket Immigration to be held in detention pending deportation, under Immigration Bureau order No. 8.
Two other female detainees were in the cell at the time, police noted.
The report made no mention of the two cellmates attempting to prevent Ms Htike Darlee from hanging herself.
Her death is being treated as suicide.