The Metropolitan Police has asked its employees to delete from its database any images that show officers with hidden identity numbers, according to a leaked email.

First revealed by the London Evening Standard, the new policy asks for all images showing police officers without their numbers to be deleted. The email reads: 'As of now, any still or moving photography or images of police officers must show them wearing their correct shoulder numbers/markings and name badges if these areas of uniform are included within the shot.'

It continues: 'If any of these items are missing the photography or images must not be used. As a precaution, if you hold any photography or images that do not meet this instruction they should be culled from your libraries.'

The Metropolitan Police has denied that it was trying to re-write history. 'Any suggestion the Metropolitan Police is looking to re-write history is absolute rubbish,' the Met told the London Evening Standard.

The policy comes after police officers were accused of hiding their identity while confronting protesters at this year's G20 summit in London.