SCHOOLS have been told to make sure private tutors have not given "inappropriate levels of support" to pupils when completing work to help decide grades this summer.
Exam boards have also been warned to look out for parents who might try to influence grades by applying pressure.
All GCSE, AS and A-levels exams have been cancelled for a second year due to disruption faced by young people.
The controversial algorithms that saw thousands receive lower grades last summer have been scrapped.
More weight will be given to the professional judgement of teachers.
The CCEA exams board has also sent schools papers in each subject which pupils can sit, to help predict grades.
While these are optional and intended to help schools get more evidence to award results, CCEA has advised schools to use at least one in each subject.
Those in exam years 12-14 only went back to classes last week for the first time since December.
Teachers will be able to draw on a range of evidence when determining pupils' grades, including mock exams and coursework.
These additional materials can be set as a test, including remotely if required, or as a class or homework activity.
New guidance from the Joint Council for Qualifications (JCQ) said robust mechanisms should be in place to ensure that teachers are confident that work used as evidence is the pupils' own and that "no inappropriate levels of support have been given".
It added that exam boards should be informed of pupils who continue to "inappropriately attempt to pressure" teachers over grade decisions.
Any "credible allegations" will be dealt with under the JCQ's suspected malpractice policies and procedures.
This could lead to sanctions against pupils, such as loss of marks or disqualification.
The guidance warned: "It is possible that some students may attempt to influence their teachers' judgements about their grades. Students might attempt to gain an unfair advantage during the centre's process by, for example, submitting fabricated evidence or plagiarised work.
"Students, or individuals acting on behalf of a student, such as parents/carers, might also try to influence grade decisions by applying pressure to centres or their staff.
"Awarding organisations will be investigating instances where it appears evidence is not authentic."
Head teachers are concerned that schools only have a few weeks before they must submit grades to exam boards.
Pupils will receive AS and A-level results on August 10 followed by the release of GCSE results on August 12.
