Lawyers for almost 70,000 women whose personal details were hacked by ransomware gang Nova, are investigating if there are legal grounds to launch a mass claim against test processing lab Clinical Diagnostics.

The hackers stole the names, addresses, ID numbers and test results of some 485,000 women who had participated in a mass screening for cervical cancer. The data of some 50,000 patients at doctors’ surgeries and other care institutions was also accessed.

The hack took place at the beginning of July but was only made public some two weeks ago.

“We are getting calls from women across the country every few minutes, saying they want to participate,” lawyer Michaël Dol told broadcaster NOS on behalf of legal firm Van Diepen Van der Kroef.

The firm, which opened a special platform for the victims of the leak on Friday, said its initial aim is to see how many people feel duped and if there are legal grounds for a collective claim for damages.

According to lawyer Sven van Doorn, who is not involved in the case, it is too early to say if such a claim would be successful. “Too little is known about what happened. A data leak is not in itself a breach of the law. The first step is to find out if there was negligence or a breach of a legal duty of care,” he said.

Privacy watchdog Autoriteit Persoonsgegevens (AP) is currently investigating if Clinical Diagnostics breached privacy rules, and the youth care inspectorate is carrying out a probe into data security at care institutions.

The data of over 50,000 people were published on the dark web but was removed after Clinical Diagnostics paid an undisclosed sum to the hackers.

Nova then threatened to publish more because the clinic had broken an alleged agreement not to involve the police. It has since claimed it has deleted the stolen data.