Thousands of police records accidentally wiped from a major crime database are “recoverable” but retrieving them will take “some weeks”, the Home Office’s most senior civil servant has said.

Some 400,000 records are feared to have been wiped from the Police National Computer due to human error as a result of defective code.

Officials are working to try and reinstate the information and an internal investigation has been launched to find out how the blunder occurred.

Home Office permanent secretary Matthew Rycroft told MPs this was the “maximum” amount of records which may have been lost and insisted any risk to public safety was “minimal”.

Speaking to the Public Accounts Committee on Monday, he said: “I can assure the committee the risk to public safety is minimal.

“All of those deletions refer to what’s called ‘no further action’ cases.

“We are confident that the data is all recoverable and we are in the process of recovering that data.

“Over 99% of the potentially deleted records are over 10 years old.”

Mr Rycroft said the error took place after coding was “erroneously” entered into the system, but added: “The team are working flat out.

“They are seeking to recover all of the data as rapidly as possible, but as you would expect they are taking great care over that process in order not to compromise the data itself or the rest of the systems on the computer.

“So they are taking their time. It will take some weeks.”

He also stressed that police forces can turn to other data sources while the problem is being fixed, adding: “We can be confident that we are going into the right direction on this one.”

An estimated 213,000 offence records, 175,000 arrest records and 15,000 records on people were potentially incorrectly deleted.

This is believed to include 26,000 DNA records and 30,000 fingerprint samples.

Last month the Prime Minister said it was “outrageous” that police records had been deleted and called any loss of data “unacceptable”.