A key witness in a fire incident has been asked by the police to undergo a polygraph lie detector test.
The Sri Lankan maid, known only as Rani, is believed to be the last person to see her employer, Madam P. Lakshmi, alive before the Owen Road flat they lived in was engulfed in flames on Wednesday.
Family members of the 92-year-old victim told The Straits Times last night that Rani had been asked by police investigators to take the test.
A polygraph measures a person's breathing rate, pulse rate, blood pressure and galvanic skin reflex, to determine if he or she is lying.
Polygraph evidence, however, remains inadmissible in court, but law enforcement agencies here have reportedly been using the instrument to assess the credibility of witnesses and suspects since 1977.
The maid had been living with Madam Lakshmi in the one-room rental flat for the past six years.
The older woman was found dead after firefighters put out the flames on Wednesday evening.
Rani had apparently left Madam Lakshmi alone at home to buy beedi, an Indian cigarette, for her employer, who could move around only on a wheelchair.
Neighbours said they saw Madam Lakshmi having coffee with the maid at the nearby coffee shop, earlier. The two women had just returned from Madam Lakshmi's appointment at Tan Tock Seng Hospital.
Ms Nisha Abdul Rahim was one of four neighbours who rushed into the seventh-floor flat to save the elderly woman when the fire broke out.
The 39-year-old told The Straits Times that Madam Lakshmi recently complained to her that Rani would shout at her and that she would rather live in a home for the elderly than with the maid.
The telemarketer added that Madam Lakshmi would leave her door open but with the metal gate closed and unlocked throughout the day, in case of an emergency.
Ms Nisha said when she and three other neighbours rushed to the flat, she saw the bed frame on fire, but had to leave because the smoke was too thick.
Madam Lakshmi's body, which was burnt beyond recognition, has yet to be released to the family.
When The Straits Times visited the scene yesterday, the walls along the entire floor were blackened, with the acrid smell of soot lingering.
Outside the elderly woman's unit were remnants of prayers offered for her.
The case has been classified as an unnatural death and investigations are ongoing.