PSNI data breach: Police Federation chair urging all police officers and staff to exercise maximum vigilance

Mr Kelly said: “Since this major data breach, and subsequent breach, the PSNI was operating on a working hypothesis that the information on all police officers and staff would end up in the hands of dissidents and organised criminals.

“The chief constable’s announcement therefore comes as no great surprise. However, it makes it all the more imperative for each and every colleague to exercise maximum vigilance. We must do all we can to frustrate and prevent attacks on our colleagues and their families.

“Our men and women are resilient and resourceful. They must call on all their training and professionalism to counter this ugly consequence of a monumental data breach.

“Even though we believed from the outset the data would find its way into the hands of people intent on murdering or maiming our colleagues, it is obviously a deeply worrying development.”

Mr Kelly added: “We have to be strong and determined to do everything we can to minimise risk and that means varying the routes we take to and from work, changing routines and reassessing our personal security both on and off duty.

“We can thwart the consequences of the violent dissident threat and rhetoric, but it will require an all-out effort by each and every one of us.”

The shadow Northern Ireland secretary has said the situation is “incredibly serious and worrying”.

Peter Kyle said: “There are many questions that need to be answered about how this terrible situation has come about, but the first and most important response that is required is to ensure the safety and security of PSNI officers and staff who are affected.

“I’m grateful for the briefings provided to me by senior officers since the leak occurred. We will continue to work constructively with the government and PSNI to ensure the right support is made available to reassure and protect those who protect us. This must be the priority.”