As the mother was unable to find the money, the teenager reportedly threatened that the entire family would commit suicide, she said.
Her former husband and two children were found hanging in the house, while her mother-in-law and sister-in-law were found dead on the ground floor.
Pol Lt-Colonel Thepwisit Phokengrit, deputy superintendent of Bang Yi Reu Police Sation, said Uraiwan Sermsak, 53 – the former wife of Anant Jarupankit, 64, and mother of Suwantip, 16, and Abhisit, 14 – said she and her husband had split up eight years ago. After the split, she took a job in the Saphan Mai area and began sending Bt900 a week to support the two children, she said.
The grief-stricken woman said her daughter had called her in November asking for Bt20,000 to cover household expenses, but when Uraiwan said she didn’t have the money, the teenager responded by saying they would all kill themselves.
The police will also check to see if the girl had been forced by her father to demand the money, or if she had initiated this herself, Thepwisit said.
He also said that about a year ago, Anant had reportedly called his younger brother to ask for Bt20,000 to Bt30,000 to cover his household expenses several times, and when the brother refused, Anant would threaten him with family suicide.
Uraiwan and relatives went to collect the bodies at General Police Hospital for funeral rites at Wat Lak Si.
Thepwisit said police believed the motive might be stress over financial woes and that they had chosen New Year’s Eve for the sake of publicity. He said police had yet to identify who added poison to the soft drinks consumed by the family members, and hanged the three. Forensic test results should come out in 15 days.
Pol Colonel Thaprawit Inthachai, Bang Yi Reu superintendent, said police would interview neighbours and look for more leads at the scene. Police found a mobile phone, believed to be owned by Abhisit, in a bedroom on the second floor and some school papers.
Police suspect a family member is behind the deaths as there are no signs of fighting or ransacking.
A police spokesman said officers were waiting for a toxicology report conducted on Anant’s mother and sister to see if they were poisoned and if so, what with.