Murat Dizdar, Deputy Secretary of School Performance said the department had followed all health advice.

He said, after being informed late on August 10 of the positive tests at Batemans Bay High and Public Schools, staff had worked with NSW Health to identify close contacts.

"NSW Health are contacting the students, their families and the staff members who are identified as close contacts," Mr Dizdar said.

He said attendance records were examined for the days the students were deemed infectious. Their movements through the day were identified.

"In a high school, students move from lesson to lesson and those lessons and students and staff are identified by NSW Health," he said.

"In a primary school they tend to be more contained to a class.

"Let me assure both school communities they will be contacted by NSW Health if they are deemed to be a close contact.

"They will be provided advice for the duration they need to isolate."

Anyone suffering flu-like symptoms would be advised to get tested.

The schools would also write to the families of all close contacts.

"The rest of the school is deemed as a casual contact," Mr Dizdar said.

"They do not need to self isolate; they will be able to resume coming to school (once cleaning was completed) unless they are unwell."

Mr Dizdar said the well being of everyone, including those infected, came first.

"There are two students here and their families who are confirmed as positive and we need to do all we can to support them," he said.

He acknowledged the difficulties Year 12 students at Batemans Bay High School had already faced after bushfires and said the HSC had been delayed by five days, to October 19.

"It has been a very challenging year," Mr Dizdar said.

"We ask all our students to focus; they still have time here."

He said students could approach staff, welfare teams and councillors.

If an HSC student missed oral or performance exams due to being unwell, alternative arrangements could be made.

If a sick student missed a written exam, they could also apply for consideration.

Mr Dizdar said teachers had shown "remarkable commitment" during the pandemic and had given HSC students extra lessons, catch-up classes and email support.

"Teachers have been enormously giving of time and expertise," he said.