A Sydney laboratory has apologised after hundreds of people were told they had tested negative for COVID-19 when they were positive.
"SydPath last night incorrectly messaged more than 400 people, advising them they had tested negative to COVID," SydPath said in a statement.
"These people had tested positive to COVID.
"As soon we became aware of the issue this morning, SydPath immediately commenced a process to contact impacted people.
"An emergency response team is now investigating the cause of this mistake, which is believed to be human error.
"We sincerely apologise to all those impacted."