Illinois State Police have been given the go-ahead for the first 'drone cops'.

The Federal Aviation Authority has given the force approval to use drones to photograph crash and crime scenes.

Cops say aerial photographs taken from drones will cut down on the time highways are closed during investigations of major traffic crashes.

The announcement says the program 'is not being implemented for surveillance purposes' and refuses to call the craft being used drones.

The police agency announced Friday that the Federal Aviation Administration has authorized what it calls its Unmanned Aircraft System program.

The announcement says the program 'is not being implemented for surveillance purposes.'

The Illinois State Police says it worked with lawmakers and civil rights groups to ensure privacy concerns were addressed.

The agency says it's avoiding the word 'drone' because 'it carries the perception of pre-programmed or automatic flight patterns, and random, indiscriminate collection of images and information.'

The ruling allows law enforcement agencies to use a UAS only in certain circumstances, such as natural disasters, searches for missing persons, documenting traffic crashes and crime scenes, or if the Department of Homeland Security identifies a specific risk of terrorism.

PC Derek Charlton of Merseyside Police operates their new aerial surveillance drone in Liverpool. Officers in Merseyside to track criminals and record anti-social behaviour.

Except in emergency situations, a search warrant must be obtained before the UAS can be used on private property.

Any information gathered by the UAS must be destroyed after 30 days, and must not be disclosed unless reasonable suspicion exists that the information contains evidence of criminal activity, or is relevant to an ongoing investigation.