The case is in addition to the ‘small number of cases’ which the government yesterday said had been confirmed at the school and Victoria College.
In a statement, the Education Department said: ‘The affected student is isolating at home, along with the rest of their household, and is following the public-health guidance.
‘In order to respect the privacy of the individual no further information will be provided about them.
‘While the direct contacts of the student are identified and contacted, the year group have been asked to go home and to remain at home until this process is completed. Siblings in other year groups can attend school as normal.
‘The college will remain open following advice from Environmental and Public Health.
‘To protect the identity of this student and respect the family’s privacy, we will not be commenting further.’