The retired judge Sir John Mitting has been leading a public inquiry examining the conduct of undercover police officers who spied on more than 1,000 political groups between 1968 and at least 2010. At least 139 undercover officers in deployments typically lasting four years were sent to infiltrate mainly leftwing and progressive groups. Undercover officers regularly deceived women into long-term sexual relationships. At least four of the undercover officers are known or alleged to have fathered children with women they met during their deployments. So far, between the mid-1970s and 2010 at least 20 police spies are known to have formed sexual relationships with women without disclosing their true identities. Many of these undercover officers were unmasked by the women themselves after long investigations. The undercover officers joined political groups and pretended to be activists. However, their real job was to collect information about the campaigners and their protests and send secret reports back to their bosses. Another issue under the microscope is how activists were allegedly unjustly convicted for offences connected to protests because key evidence gathered by the undercover officers was concealed. Are undercover police still infiltrating political groups? It is difficult to know. Mitting told police he wanted to know if undercover officers were currently been used to spy on political groups. No answer has been given in public so far.