Undercover police officers working for Britain’s largest force used the identities of dead children and issued fake passports in their names.

Scotland Yard said it is investigating “past arrangements for undercover identities used by SDS (Special Demonstration Squad) officers”.

The Guardian reports that the Metropolitan Police authorised the practice for covert officers infiltrating protest groups without consulting or informing the children’s parents. Over three decades, officers went through national birth and death records in search of suitable matches, the newspaper said. The creation of aliases resulted in officers being issued with official documents such as driving licences and national insurance numbers.

On Sunday night, Scotland Yard said the practice was not “currently” authorised. It also announced an investigation into “past arrangements for undercover identities used by SDS (Special Demonstration Squad) officers”.

The newspaper reports that the practice was adopted to lend credibility to officers working undercover and provide them with a back story while spying. One officer, who adopted the fake persona of Pete Black while undercover in anti-racist groups, told the Guardian he felt he was “stomping on the grave” of the four-year-old boy whose identity he used. “A part of me was thinking about how I would feel if someone was taking the names and details of my dead son for something like this”, he said.

Another officer, who used the identity of a child car crash victim, said he was conscious the parents would “still be grief-stricken”, but argued his actions could be justified because they were for the “greater good”. Both officers worked for the SDS, which the police claim was disbanded in 2008.

A Scotland Yard spokesman said, “A formal complaint has been received which is being investigated by the DPS (Directorate for Professional Standards) and we appreciate the concerns that have been raised. The DPS inquiry is taking place in conjunction with Operation Herne’s investigation into the wider issue of past arrangements for undercover identities used by SDS officers”.

On Tuesday, Metropolitan police’s deputy assistant commissioner Patricia Gallan admitted to a parliamentary inquiry that another undercover unit had stolen the identities of dead children. More than one hundred families are now said to be involved, with identity theft acknowledged to have taken place as recently as the late 1990s. This relates to a second unit, the National Public Order Intelligence Unit, which gathers information on protestors. The NPOIU only began operating in 1999.

Speaking on BBC Radio 4’s Today programme, former director of public prosecutions Lord Macdonald called for a public inquiry into the operation of undercover investigations, arguing that unacceptable practices might still be in use today. He said it was “really worrying” that police chiefs appeared not to have entirely ruled out a repeat of recently exposed cases of officers entering long-term sexual relationships with members of organisations targeted.

This is a reference to the case of Mark Kennedy, an undercover cop, who infiltrated an environmental protest group. He went so “deep” that he fathered two children under his assumed identity while still being married with a son.

The Guardian first began raising the details of the undercover operation and Kennedy’s role within it in 2011. They revealed that “undercover police have been living double lives for several years among protest groups, sometimes residing with female activists and spending weeks abroad with them on holiday. At the end of their deployment, the police spies vanished without a trace”.

The surveillance operation to plant long-term spies in protest groups continues under the remit of an initiative to combat what police call “domestic extremism”.

United Nations Special Rapporteur Maina Kiai made a ten-day fact-finding tour to London, Belfast and Edinburgh before producing his preliminary report calling on the British government to launch a judge-led public enquiry into the “shocking” case of Kennedy and other undercover police officers who have been infiltrating protest groups. Kiai met campaigners, senior police officers, civil servants and the Home Secretary Theresa May who told him a full enquiry into undercover policing “was not something on the agenda”.

Eleven women and one man are bringing a High Court legal action for the emotional trauma suffered as a result of “deeply personal” relationships they formed with men who turned out to be police officers. Last week a judge ruled that some of these claims should be heard by the Investigatory Powers Tribunal, an obscure body that usually deals with complaints against MI5 and MI6.

Mr Justice Michael Tugendhat cited the fictional case of James Bond to argue that when parliament introduced legislation allowing covert police to form personal relationships with targets, they must have assumed they may have sexual encounters.

The government continues to oppose an inquiry. Instead it is trying to defuse the issue by splitting it into fifteen separate reviews of the conduct of Kennedy and related cases. However, these latest revelations show once again how the capitalist state uses its undercover police to spy on and attempt to destabilise oppositional protest tendencies and workers organisations.

This cannot be combated putting pressure on the bourgeois judicial system. Just as with the Leveson Inquiry into press ethics, such inquiries are designed to prevent the truth from coming out.

The critical issue is to carry out an unremitting struggle to expose the full impact that the decades-long spying operations by state agents have had on the workers’ movement. Tory and Labour governments have both used them to undermine the basic democratic rights of the working class.

The Guardian says it has seen a document that “indicated around 80 officers used such identities between 1968 and 1994”. This covers a significant period in the history of the class struggle in Britain and Europe. From the May-June 1968 revolutionary movement in France and the upsurge in mass strike struggles in Britain throughout the 1970s through to the defeat of the 1984-85 miners’ strike.