A year on from the first disclosures about Mark Kennedy, many are arguing for a proper inquiry into a murky, secret world

Today we are posting a guest blog by Olly Knowles, an activist who argues that there should now be a full public inquiry into the controversies surrounding the undercover policing of protest groups. His blog is here.

Police chiefs and prosecutors have been obliged to set up 12 separate inquiries over the past year to examine allegations of misconduct over the deployment of police spies. But all of them have been held behind closed doors.

Many believe that this is simply not good enough.

Knowles was spied on by Mark Kennedy, the policeman who spent seven years infiltrating the environmental movement. He was one of the activists who was arrested over the interrupted plot to occupy the Ratcliffe-on-Soar power station in 2009. He and five others were due to go on trial in January last year but prosecutors abandoned the case after it emerged that secret surveillance tapes recorded by Kennedy had been withheld from defence lawyers.