Personal details on over 21,000 current and former PN members have been leaked online after the Nationalist Party refused to pay a ransom to cyberhackers.

The data was stolen in March by a group called Avvadon Ransomware.

It is understood that the leak includes names, ID card numbers, phone numbers and addresses stolen from a database containing personal details of current and former party members. The data was uploaded to a forum on the dark web.

The hackers had threatened to leak “valuable” information unless the PN cooperated with them. It had originally given the PN a 10-day deadline.

Earlier this month, the party said the deadline had been extended but said it would not cooperate with “cyber terrorists or criminals."

The hackers had demanded €5,000 in exchange for not publishing the data.

It is believed that the data stolen by the hackers is from 2014 or earlier.

A police investigation and magisterial inquiry are underway.