The culprit is pretty bold to have change the answers in such a short time span.
Cheating is a serious offence in major examinations like that and its even more so for a teacher!
So what could have made the culprit took such a great risk?
And who exactly was the person who called in? Did he/ she saw witness something?
SINGAPORE: Baffled and shocked - these were the reactions when teachers heard about Mother Tongue (Tamil language) papers that were allegedly tampered with in this year's Primary School Leaving Examination (PSLE).
The incident, said to involve a teacher making changes to answers in three exam scripts - after they were submitted by the pupils - would be the first time PSLE scripts are known to have been altered.
The Ministry of Education (MOE) is not revealing the name of the school yet as it has called in the Corrupt Practices Investigation Bureau, and investigations are in progress.
A media report on Monday placed the school as being in the north, after an anonymous call was received.
The report said that answers in a pupil's composition paper had been altered and some answers in the fill-in-the-blanks section were cancelled and replaced with other answers. Similar changes were found in a section of the scripts of two other pupils.
The Singapore Examinations and Assessment Board (SEAB) said it could not provide details of its operations during the PSLE, but teachers who have invigilated the exam said there is "almost no way" to alter the papers.
"The security is very tight," a primary school Tamil language teacher with 10 years of experience told Today.
"The collection of papers is done very, very quickly and they are sent to the examination centre almost immediately."
"There would be two other exam officers present."
Another primary school teacher said that internal invigilators from a school usually do not oversee the exams of the subjects they teach - at least in his school.
"If a candidate has a question about the paper, the invigilator will call someone over from the collection point. They leave nothing to chance," he said.
"After collecting the papers, you take them to the central collection point which is either a room next door or one level below the exam venue where they would be sealed.
"It's a very short window period - I'd say barely a minute, because if you don't turn up at the collection point promptly, the people there will suspect (that something is amiss)."
The altered answers, which were discovered during the centralised marking of the PSLE papers from 16 to 19 Oct, had reportedly been scribbled in haste, in a different colour and in different handwriting.
The SEAB's chief examiner for Tamil language has since marked the scripts based on the pupils' answers, which were still visible.
The MOE said it "takes a serious view of this matter" and that any MOE staff member "involved in compromising the integrity of the examination system will have to face disciplinary action".
The news comes the week PSLE results are being released. The MOE announced on Monday that pupils may collect their result slips from noon on Thursday.