US plans to electronically monitor workers with security clearances

Monitoring system will link to up to 40 outside databases - including credit agencies and, potentially, medical records

US security services are planning to use an electronic monitoring system to keep an eye on the activities of staff - and to prevent another Edward Snowden-style leak of internet documents and information.

Almost four million US government employees currently hold privileged security clearances and would be subject to surveillance under the new initiative.

The monitoring system is intended to identify "rogue" agents, corrupt officials and people like Snowden intent on leaking information, according to Associated Press, which claims to have seen documents outlining the new system.

Similar to the monitoring systems already in place with such organisations as banks, it will include research from the Pentagon's Automated Continuous Evaluation System (ACES), which was developed with the help of defence contractor Northrop Grumman at a cost of $84m.

"According to project documents, ACES links to up to 40 databases. While many are government and public data streams already available, ACES also taps into the three major credit agencies - Experian, Equifax and Trans Union," according to AP.

It follows a review of the US government's security clearance processes instigated by the leak of documents by whistleblower Edward Snowden.

However, privacy activists and unions said that the monitoring could also be intrusive and undermine staff privacy, prompting flawed investigations and putting sensitive personal data at greater risk.

Lee Tien, a senior staff attorney with the Electronic Freedom Foundation, a civil liberties group, told AP that staff free speech, political allegiances and outside activities could be affected by the new monitoring system.

Indeed, officials developing ACES had considered also linking medical and mental health records to the system, but passed that decision instead to politicians to decide.

Workers with secret clearances are already required to undergo background checks of their finances and private lives before they are hired and again during periodic re-investigations.

"What we need is a system of continuous evaluation where when someone is in the system and they're cleared initially, then we have a way of monitoring their behavior, both their electronic behavior on the job as well as off the job," Director of National Intelligence James Clapper told Congress last month.