Parents of dead children whose identities were used by undercover police must be told what has happened, an MP has said.
Scotland Yard's Special Demonstration Squad used the details over three decades in order to give fake personas more credibility, the Guardian reported.
The Metropolitan Police authorised the practice for covert officers infiltrating protest groups without consulting or informing the children's parents, the newspaper said.
Chairman of the Home Affairs Select Committee (HASC) Keith Vaz told Sky News: "What is absolutely vital is that the parents of those involved should be informed immediately. It can't be right that this information is being kept from them."
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. He said: "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."
A document seen by the newspaper indicated around 80 officers used such identities between 1968 and 1994, it was reported.
Former director of public prosecutions Lord Macdonald called for a public inquiry into the operation of undercover investigations, warning 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 sexual relationships with targets.
Public confidence in a vital part of the fight against organised crime was at risk as the police appeared to have "completely lost their moral compass", he told the BBC Radio 4 Today programme.
"How are you supposed to maintain a level of fair and objective evidence-gathering if you are having sex with the person you are targeting, fathering a baby and then abandoning it, using a dead child's identity?" he asked. "These are all examples of areas in which the police have completely lost their moral compass and have completely failed to understand the boundaries."
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. T he 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. We can confirm that the practice referred to in the complaint is not something that would currently be authorised in the MPS (Metropolitan Police Service)."