When her six-year-old son Joel (not his real name) started refusing to attend kindergarten and claimed that his teacher had hit him with a pen, Madam Lee, 37, thought he was just being rebellious and spoilt.
He had also started coming home with small bruises on his hands and legs, but the business development manager, who declined to use her full name to protect her child, did not pay much attention to them.
She assumed that he would, like any active boy, get small scratches and bruises while playing at school.
But one night last month, Joel became very insistent on not going to school the next day and Madam Lee sensed that something was wrong.
The pre-schooler said that his teacher at Zoo-phonics School in Bukit Timah would hit his hand with a pen to discipline him.
He also claimed she would push and shake him violently whenever he did not know the answer to a question or made a mistake in his work.
Joel also said that the teacher, whom Madam Lee knows as Teacher Kris, would often raise her voice at the class and would forcefully press workbooks against their chests when handing the books back to them.
Madam Lee, who is a single parent, told The New Paper: "He kept saying, 'Mummy, I don't want to go to school, teacher beat me'.
"He was very fearful and sounded so traumatised by school.
"Usually, if he is lying, I will threaten to call the police and he would be scared and say 'just kidding'.
"But when I did (make the threat), he said very confidently that he would tell the police about his teacher. So I started taking it seriously."
Zoo-phonics School is a private enrichment centre registered with the Ministry of Education (MOE).
It runs kindergarten and enrichment classes at franchises island-wide.
Madam Lee also found out that another child, Kate (not her real name), had received the same treatment from the same teacher. She learnt this when she spoke to Kate's mother one day while picking Joel up.
Both mothers had transferred their children to Zoo-phonics School from other kindergartens this year because they thought the curriculum would be better.
Kate's mother, who wanted to be known only as Madam Lim, told TNP: "Kate used to love her teachers, her friends and going to school.
"But gradually, she started saying that she didn't like Teacher Kris any more because she would scold or punish at her."
Madam Lim, a housewife in her 40s, has two older children.
She said she regrets not believing her daughter earlier.
"I thought Kate was just being sensitive and that her teacher was giving her a friendly nudge. But when my bubbly and friendly girl started refusing to go to school, I thought, maybe all those things she said were really true," she said.
Both parents went to the school last Monday to speak with the teacher and the principal.
The mothers said the principal defended the teacher's actions and called the discipline methods "firmer than usual".
They also said the principal insinuated that their children had been lying about the abuse to get attention.
Said Madam Lim: "Initially, I just wanted an apology from the teacher to Kate. But after the principal said that my daughter was lying, I decided that I couldn't take this lying down."
Both mothers lodged a police report later that night and pulled their children out of the school the next day. Police confirmed that the reports were made and investigations are ongoing.
Both mothers have also taken the matter up with MOE and Madam Lee has also contacted the Prime Minister's Office.
An MOE spokesman said they are looking into the matter.
When contacted, Mr Vincent Teoh, director of Zoo-phonics School Asia, refused to comment, saying the matter was under police investigation.
But he said Teacher Kris had resigned last Thursday.
He said: "We do not condone inappropriate or abusive behaviour and if teachers or staff are proven to commit such acts, they will be disciplined or dismissed.
"We also have a policy that teachers are not meant to touch the children."
TEACHER'S ACTIONS 'DISTURBING'
Three psychologists and psychiatrists The New Paper spoke to about Kate's and Joel's experiences said the allegations of the teacher shaking and pushing the young children were shocking and "disturbing".
Dr Brian Yeo said: "Teachers should never react violently or forcefully, unless to prevent immediate violence or danger. While the teacher's actions might cause an immediate response for the child to behave, such shock tactics don't benefit the child in the long term."
While the children might have done something wrong, teachers have no autonomy to use force on them, said Ms Sheena Jebal, adding: "This is not exactly child abuse in the physical sense, but more emotional abuse as these acts can come with public humiliation."
"Using such punitive methods to teach the child... can lead to psychological effects like school refusal and a dislike for studying."
Dr Lim Boon Leng, a psychiatrist, said long periods of physical discipline can lead to nightmares, trauma and even to children re-enacting these scenes with friends and siblings. He said studies have shown that corporal punishment can make the child more violent and aggressive.
This article was first published on October 12, 2015. Get The New Paper for more stories.