The use of dead children’s identities by Scotland Yard undercover police officers was “common practice”, a chief constable investigating the matter has found.
In a letter to MPs, Mick Creedon, who is leading Operation Herne, said no families of children whose identities were used had been contacted and informed.
Mr Creedon, the Derbyshire Police chief who was brought in to take over the investigation from the Metropolitan Police in February, said: “This issue is very complicated and mistakes could put lives in jeopardy.”
Herne was set up in October 2011 to look into allegations made against the Met’s special demonstration squad (SDS), including using dead children’s identities and engaging in inappropriate sexual relationships.
Mr Creedon was responding to questions from the Home Affairs Select Committee.
Answering how many dead children’s identities are estimated to have been used by undercover police, he said: “I am not able to answer this question at this time with any degree of absolute certainty but I can say that this was common practice within the SDS.”
Mr Creedon confirmed that Scotland Yard has received a number of speculative inquiries from relatives asking the force to confirm that their dead child’s identity was used.
He said: “No families of children whose identities have been used have been contacted and informed.
“No answer, either positive or negative, has yet been given in relation to these inquiries from families.”
The chief constable said it would not be “appropriate” to provide details on the number of children the Meropolitan Police has identified as being born out of a relationship with undercover officers.
Mr Creedon said there are currently 34,000 computer files, equal to 50,000 individual documents, yet to be processed.
The investigation, which has 23 officers and 10 police staff working on it, has cost £1.25m and is expected to cost another £1.66m over the next year, he added.
No arrests have been made and no officers have faced disciplinary proceedings, the chief constable said.
Mr Creedon added: “Unravelling all the complexities of this is going to take a considerable effort and not a little time.”
MP Keith Vaz, chair of the Home Affairs Select Committee, said: “With 50,000 documents to go through and years of undercover police operations to examine, it is vital that Herne does not go the way of the original phone-hacking investigations. It is imperative that a timetable is set for completion of the operation, and the victims informed and apologised to as soon as possible.
“In particular, the families of dead children whose identities were used, the offspring conceived by police officers using their undercover identities and those who had sexual relations with them using their alias must be contacted as a matter of urgency.”