Sararat Rangsiwuthaporn was nabbed at the Chaeng Watthana Government Complex in Bangkok in line with an arrest warrant issued by the Criminal Court.
Police said a bottle of cyanide was also found in her possession and that she will be charged with first-degree murder.
Last week, the mother of Niphawan Khanwong, a 32-year-old businesswoman in Kanchanaburi, filed a complaint with deputy national police chief, Pol General Surachate “Big Joke” Hakpal, about the mysterious death of her daughter.
The mother, Thongpin said Sararat had befriended her daughter before taking her on a merit-making trip to a temple in Ratchaburi’s Ban Pong district on April 14.
During the trip, Niphawan suddenly collapsed and died soon after. Autopsy results showed heart failure as the cause of death.
Police said CCTV footage showed that Sararat was present when Niphawan collapsed, but did not try to help.
Thongpin said she decided to contact Surachate personally because she was afraid Sararat would use her ex-husband’s influence to block the investigation. Her former husband is the deputy chief at Ratchaburi Police Station.
The victim’s mother said she suspects her daughter was drugged by the suspect, who later stole her money and jewellery. She added that her daughter was known to be wealthy.
After the arrest, Surachate said that on April 1, a police major’s relative had complained that the major had had a seizure and died while visiting Phra Pathom Chedi temple in Nakhon Pathom with Sararat.
The major’s relative also said she had withdrawn 140,000 baht the day before the trip, but when they went to pick up the body, the money was missing.
Surachate said police are investigating similar mysterious deaths that may be linked to Sararat, adding she may have committed similar crimes several times.