Undercover police officers have spied on more than 1,000 political groups since 1968. However, no official list of these groups has been published.

This database is an attempt to compile such a list. It is a work in progress and will be updated as more information is made public. The aim is to make more visible the nature and scope of a covert operation that has spanned more than four decades.

The information has been compiled following investigations by the Guardian and the Undercover Research Group, a network of activists that scrutinises the covert infiltration of political movements. The group is also publishing a similar database.

The HN or EN ciphers have been allocated to individual officers at a public inquiry that is examining the infiltration.

Explore the list of groups that were spied on