Over 500,000 names on the DNA database are false, misspelt or incorrect, the Government has admitted.
Ministers have disclosed that one in seven of the genetic profiles on the controversial database is a "replicate", raising alarming questions about the integrity and accuracy of the entire system.
Around 4 million names are on the database, which is the biggest in the world, and holds details of rapists, murderers, and suspects arrested but not charged.
Thousands asked to give their details to police upon arrest have given false names or alternative spellings of their names. In other cases, mistakes have been made in the spelling of names. Some files include names belonging to someone else, or names of people who do not exist. Altogether there are 550,000 "replica" files.
If the Home Office cannot run a database of 4 million entries, how will it cope with a database of nearer 60 million entries?