An urgent investigation is needed after DNA profiles and fingerprints of scores of potential terror suspects were wrongly deleted, ministers have been told.
It came after a watchdog revealed that the issue - first revealed in a report earlier this year - was more widespread than originally thought.
The blunders relate to a system rolled out in 2013 which means biometric records of people who are not convicted of a crime should be erased.
However, the details can be retained when police make a "national security determination" (NSD).
In his annual report in March, Biometrics Commissioner Alastair MacGregor disclosed that by October 31 last year, handling and other delays had led to a situation where the retention periods for biometric records of at least 450 individuals expired before NSDs could or had been made.
It was thought at that time the determinations may have been applied for in about 45 of those cases.
However, in an updated report published on Thursday, Mr MacGregor said it now appears that by the end of March this year, retention periods applicable to the biometric records of around 810 individuals expired before the NSD process had been completed.
In the majority of the cases the biometric material in question was taken in the context of an examination under powers set out at Schedule 7 of the Terrorism Act 2000, the report said.
Mr MacGregor went on: "I t is now my understanding that applications for NSDs would undoubtedly have been made in at least 108 of the cases that had in fact expired by March 31 2016 and that the actual figure might well have been appreciably larger."
He said the fact that a large amount of material has fallen to be deleted "before a proper assessment has been made of the extent to which its retention would be desirable on national security grounds is, of course, a matter of real concern".
He added: "Given that, as a result of the problems referred to above, the biometric material of a significant number of individuals has been lost in circumstances where that material could and should have been retained on the grounds of national security, it is obviously very important that steps quickly be taken to establish whether - and, if so, how - replacement material should be obtained from those individuals and/or other action should be taken to minimise any risk which they pose to national security."
The Commissioner said that he is now "broadly satisfied" that steps were being taken to address the problems he raised.
Shadow policing minister Jack Dromey described the error as "inexcusable".
He said: "Theresa May and the Home Office have very serious questions to answer about what went wrong.
"Fingerprint and DNA data can be crucial in police operations to combat serious crime and terrorism."
Labour MP Keith Vaz, chairman of the Commons Home Affairs Committee, said: "It does little for public confidence when important data is being deleted because paperwork is not being completed on time.
"There needs to be an urgent investigation to get to the root of this problem, but the Home Office must get a grip of how data is being managed to prevent issues like this from damaging our national security."
A Home Office spokeswoman said: "The Commissioner has concluded that steps are being taken to address these issues, and the police have provided further assurances that they will be kept under close review."
Assistant Chief Constable Alan Barr, deputy senior national co-ordinator for counter-terrorism, said: "This was a result of a number of different factors across our processes.
"We have worked with the Biometrics Commissioner to develop a comprehensive plan to rectify the immediate issues and to ensure this will not happen again.
"The identity of these individuals is known and the risks they potentially pose are being managed in conjunction with partner agencies to minimise any long-term risk to the public."