EXAM chiefs have uncovered cases of apparent copying by Junior Certificate science candidates.
The work involved is science practicals done by the students at school and teachers are supposed to verify it as the candidate's own before submitting it for marking.
The science investigations, known as coursework, carries up to 35pc of the marks in the exam.
The problem occurred both among higher level and ordinary level candidates and among candidates at more than one exam centre during last year's Junior Cert.
The issue has been highlighted in a report by the chief examiner of the State Examinations Commission (SEC).
Some Ordinary Level candidates had their marks for the work involved withheld pending a satisfactory explanation from the schools, according to the report.
However, it is not known what the final outcome was for the students, who sat their exams in June 2010, as the SEC has said it does not comment on individual cases.
In cases where the SEC is satisfied that cheating has occurred, it may withhold results indefinitely or, in the worst-case scenario, ban a student from sitting future exams.
The use of coursework in assessing students is regarded as key to ensuring that students can apply their knowledge and develop necessary laboratory and science investigative skills.
The examiner's report notes that the marks awarded for science coursework were generally high, but points out that some candidates wrote "identical or very similar entries for analysis, conclusion and comment".
The report states: "The presentation of similar coursework by a number of candidates is a cause of some concern.
"Teachers and students are reminded that coursework presented and the reports thereof should be the individual work of the candidate only."
The chief examiner also criticised the way some Leaving Certificate business students memorised answers for last year's exam.
The report adds: "An over-emphasis on preparation for the examination through rote learning of answers resulted in low marks being awarded to candidates in certain questions."
Among the recommendations given to students in the report is not to rely on answers that may have been appropriate to questions in a previous year's paper.
"Questions may appear similar to previous years but the focus on the questions and the specific context of the question may vary, thereby requiring different responses," the report advises.