Officials scrambling to protect 40 officers at MI5’s HQ in Northern Ireland after data leak

OFFICIALS are scrambling to protect up to 40 officers at MI5’s HQ in Northern Ireland after a security gaffe.

The identities of dozens of surveillance operatives and police who work closely with the security services were released in an online blunder.

Cyber experts at MI5 are rushing to identify everyone who downloaded the document, which includes the surnames, initials, departments and locations of 10,000 police.

Whitehall sources expressed concern for the safety of those working undercover in anti-terror roles and within .

Members of the organised crime unit and officers based at ports and airports were also named, with for up to three hours.

The breach was declared a “critical incident” by the Police Service of Northern Ireland, while a probe into the circumstances of the leak has been launched.

Warnings were issued to anyone in possession of the spreadsheet — accidentally released in a Freedom of Information request — that it could be an offence to share.

Northern Ireland Secretary Chris Heaton-Harris has been speaking by phone to PSNI Chief Constable Simon Byrne.

He said he was “deeply concerned” about the breach.

Under-fire Mr Byrne will cut short a family holiday to face questions over the data leak, which affected all ranks and grades in the force.

The NI Policing Board will today talk with PSNI heads.

Northern Ireland’s threat level was raised to severe in March over police safety.

The wife of one officer yesterday told Sky News they were now “living in fear”.

Chris Todd, PSNI Assistant Chief Constable, called the leak “unacceptable” yesterday.

He added: “We hope for the best and prepare for the worst in situations like this.”