The personal details of 550,000 Australian Red Cross blood donors have been leaked in an event that is being described as Australia’s largest ever security breach.

In a statement released today, Blood Service Chief Executive Shelly Park said that “a file containing donor information was placed in an insecure environment by a third party that develops and maintains the Blood Service’s website.”

The hacked files contain details given through an online application to give blood, including information about ‘at risk-sexual behavior.’ Access to the files has since been shut down.

The Australian Red Cross Blood Service have attributed the breach to “human error” and say that cyber security experts have told the organization that the risk of the data being misused is low. However, they urge those that know they are registered on the blood donor register to stay alert for phone and email scams.

“We are incredibly sorry to our donors. We are deeply disappointed this could happen. We take full responsibility and I assure the public we are doing everything in our power to not only right this but to prevent it from happening again,” Ms Park said.

She added: “It is vitally important that people who generously want to give blood are not deterred by this – every Australian may need a blood transfusion at some time and we hope people will continue to make their contribution and to feel confident that their personal details will be protected.”

Anyone that thinks they might have been affected by the leak can visit this page for further support and information from the Australian Red Cross Blood Service.