Elite Auckland girls' school St Cuthbert's College is the latest victim of the coronavirus pandemic after a sports team played a match against Mt Albert Grammar.
St Cuthbert's principal Justine Mahon said the Ministry of Health has advised that all seven members of the sports team are considered to be close contacts of a player in the opposing team who tested positive for the virus.
The player is believed to be the second case of the virus at Mt Albert Grammar, who tested positive on Thursday and was believed to have been infectious between August 5 and 11.
The sports game took place on August 6. Mahon declined to name the sport to protect the students' privacy.
Mt Albert's staff and all 3000 students have also been asked to get tested for the virus, but Mt Albert headmaster Patrick Drumm has said the school will reopen on Monday even if results are not back for all students by then.
He told parents in a newsletter on Friday that the Auckland Regional Public Health Service had "confirmed that it is safe for normal lessons to resume on-site".
"With it now being close to three weeks since students were at school, the primary purpose of testing is to provide further assurance to individuals and the community that any risk of further infection is low," he said.
But Mahon said she was not willing to take the risk of reopening the senior school for students in Years 7 to 13 until all seven girls in the sports team have tested negative.
Five have already tested negative and she is now waiting for the remaining two.
The Ministry of Education has ordered all Auckland state and state-integrated schools to reopen for all students on Monday, but Mahon said private schools have "more latitude".
"I think there is a difference between low risk and no risk, so I'm waiting to hear from the final two families," she said.
"Given the recent information that has come through on how young people, particularly adolescents, can transfer the virus, I just need to make sure that we can keep everyone safe.
"I'm expecting they will be negative so we will be reopening on Monday."