Unlike other NSA programs - personal data can be accessed by up to 1,000 analysts during more than just counter-terror investigations

Purpose was to help government agents predict future threats to US

Spy agency hailed search engine, ICREACH, as landmark in US

The National Security Agency is secretly supplying personal data to 23 US government agencies using its own Google-like search engine designed to share more than 850 billion phone and email records.

The covert program was revealed in classified documents provided to The Intercept by NSA whistle-blower Edward Snowden.

The documents provide clear evidence that the spy agency has been making a huge amount of surveillance data available to domestic law enforcement agencies for several years.

Whistle-blower: Classified documents provided by Edward Snowden (above) reveal the existence of ICREACH - a search engine built to provide data on millions of people to government agencies

The search engine, named ICREACH, contains information on the private communications of foreigners as well as on millions of American citizens innocent of any wrongdoing.

Planning documents for the tool specifically name the FBI, CIA and DEA as core participants - meaning they would have easy access not only to billions of email and phone records, but also mobile phone locations and internet chat records.

ICREACH, initially projected to cost between $2.5 million and $4.5 million per year, can be used by more than 1,000 analysts working at 23 US government agencies that perform intelligence work, according to a 2010 memo.

Information shared through the program can be used to track people's movements, map out their networks of friends and potentially reveal religious affiliations or political views.

Huge-scale operation: NSA (headquarters in Fort Meade, Maryland, pictured above) hailed the creation of the secret search engine, ICREACH, as a landmark in the history of classified US government surveillance

According to the NSA documents obtained, the launch of ICREACH was a landmark moment in the history of secret US government surveillance.

ICREACH: HOW NSA USES ITS OWN GOOGLE-LIKE SEARCH ENGINE To allow government agents to make sense of the vast database of records, experts working with the NSA designed a simple Google-like search function. This meant analysts could run searches against particular 'selectors' associated with a person they were investigating such as a phone number or email address. A page of results would then be presented - displaying personal data such as a list of monthly phone calls. Such information enables analysts to form a network of data on a particular person - where they identify details such as friends, family, interests and activities. The tool was masterminded by retired NSA chief Keith Alexander. The spy agency described ICREACH as a 'one-stop shopping tool' for analysing communications. Advertisement

The search tool was built with the intention of becoming the largest system for internally sharing secret surveillance records in the country - capable of processing two to five billion new records every day.

This includes more than 30 different kinds of data obtained from emails, phone calls, faxes, internet chats and text messages, as well as location information collected from mobile phones.

Earlier revelations arising from leaked Snowden documents have exposed several NSA programs designed to collect large volumes of communications from innocent parties.

The spy agency has admitted that it shares some of its data with domestic agencies such as the FBI, but details about just how far it goes have long been a mystery.

Using Section 215 of the Patriot Act, the organisation has stored information on millions of ordinary American citizens' phone calls - which in turn has been made available to just a small number of NSA employees, as previously revealed by The Guardian.

Such information has only been accessible in relation to counter-terrorism investigations though.

ICREACH grants access to a massive set of data - which can be viewed by analysts from across the intelligence community for 'foreign intelligence'.

This allows data to be accessed on a far broader scope that just counter-terrorism.

A top-secret memo dated December 2007 noted: 'The ICREACH team delivered the first-ever wholesale sharing of communications metadata within the U.S. Intelligence Community.