Residents of Block 55, Toa Payoh Lorong 5 are spooked by the 'irregular behaviour' of an elderly couple living in a rental flat on the 10th floor.

The woman was seen hurling burning items over the parapet and splashing a seemingly corrosive liquid outside her home, causing many residents to be concerned about their safety, The Straits Times reported.

The metal gates and a stretch of the corridor outside the couple's unit were corroded, exposing bricks, metal pipes, and a pitted floor.

The bizarre incidents surrounding the couple have been going on for over two years, a next-door neighbour said.

Some days, she would find ashes and salt on her front door and windows, or her laundry on the corridor covered in oil.

Photo: The Straits Times

A 40-year-old housewife, who asked to remain anonymous, said that she has been hearing the woman shouting loudly every morning at around 7am for the past two months.

She said: "I can't make out what she says. So I just assume that she's just mentally unsound and left it at that."

According to the housewife, two officers had visited her unit last Friday (Jan 5).

"A policewoman asked me if I've had any problems with my neighbours, and I said no. She later showed me some pictures of the corridor outside the woman's flat and said that some neighbours complained of her splashing things there.

"I took a look and was shocked. It looked as though somebody had splashed corrosive liquid there."

When she and her husband went up to the 10th floor to take a look at the elderly couple's flat, they were shocked.

She said: "The area outside the woman's flat was a mess. There was a strong chemical smell in the air and we felt a stinging sensation in our eyes. We quickly left the area after that."

Photo: Shin Min Daily News

Another neighbour who declined to be named said he saw the woman throwing burning items over the parapet, and added: "I fear for my safety and that of the children living in this block."

Lianhe Wanbao reporters later visited the couple's unit and spoke to the woman, who claimed that her next-door neighbour had been intentionally pouring faeces and urine at her unit for the past two to three years.

Thus, she had to scrub and wash the place with salt water every day.

She also alleged that they would use a hammer to hit her metal gates and the wall outside her unit.

However, the alleged neighbour, Mr Ye, 80, denied the claims and said that the elderly woman's multiple scrubbing sessions each day have corroded the corridor walls and her metal gates.

He added that he did not dare to open his windows or door, and called the police over 30 times in past seven years to report his neighbours' weird behaviour.

Mr Ye, who had a stroke, said he was afraid that he might slip and fall as the corridor was constantly wet from the woman's washing.

In response to media queries, the Bishan-Toa Payoh Town Council said that the resident does not pose any danger to herself or others. It is also working with various agencies to help resolve the matter.

In a statement issued on Saturday, town council chairman Chong Kee Hiong said that grassroots leaders who visited the elderly woman's flat discovered that she had used salt, vinegar, and baking powder to scrub the wall and floor repeatedly to 'get rid of spirits'. She would also throw cold ash over the parapet.

The agencies said they are aware of her actions and have been offering help to the woman over the past few months.

Mr Chong, however, said that the woman has 'adamantly refused offers of help' despite the agencies repeated attempts.

He said: "The police are monitoring if there are adequate grounds to compel her to seek professional help, but their current assessment is that she poses no danger to herself or residents."

Although repair works were carried out, the woman continued washing the corridors.

The agencies involved also noted that the couple had been staying in the unit for over 10 years and relocating them would not solve the underlying problem.

Mr Chong said: "It would be unfair to the woman's husband to simply transfer the problem to another precinct and this may exacerbate her condition."

However, alternative housing arrangements are being considered, especially if her behaviour does not improve after receiving treatment.

The agencies also emphasized that they would take the safety of all residents into account when dealing with the issue and expressed hope that the situation would reach a satisfactory outcome.