There are more than a million innocent people on the DNA database, the government has revealed.
And this number is eight times higher than the one released by ministers in March, prompting criticism by opposition parties.
"This is a matter which ought to be debated in parliament," said shadow home secretary David Davis.
He also questioned the timing of the figures - which come amid a nationwide hunt for the killer or killers of five prostitutes in and around Ipswich.
"This is a cynical piece of news management, one of the pieces of bad news rushed out last week," Mr Davis said.
The Home Office has rejected this claim, adding that the database is a "key intelligence tool".
There are currently about 3.5 million DNA profiles on the UK database, many of which have been included since new laws allowing its expansion were introduced in 2003.
Under the Criminal Justice Act, police can take and keep DNA samples from anyone arrested for an imprisonable offence - regardless of whether they are found guilty. The profiles of witnesses and victims offered voluntarily are also stored.
And figures released last week by the Home Office show one person in three on the database does not have a criminal record or even a caution by police.
Of the 3,457,000 individuals on the DNA database, 2,317,555 have a criminal conviction or caution according to the Police National Computer.
This means more than 1,139,445 million innocent Britons have their DNA on record. In March the Home Office said there were 139,463 innocent people on the database.
This is not the first time the database has come in for criticism.
Last month Alec Jeffreys, who developed many of the techniques for DNA fingerprinting and DNA profiling, said there was "mission creep" in the role of Britain's national DNA database which meant it was increasingly holding information on innocent people, rather than simply criminals, as was originally intended.
"There are now hundreds of thousands of perfectly innocent people populating that database, people who have come to the police's attention for example being charged with a crime but subsequently released," he said.
"Their DNA remains in that database. My view is that this is discriminatory - that those people are very skewed socio-economically and ethnically."
In October Tony Blair championed the benefits of the DNA database on a visit to the Forensic Science Service, revealing that he had volunteered his own profile to be added and stating that he believed there should be no limit to how many people were included.
Police have stressed the benefits of the database in fighting crime - for example, the burglary detection rate when there are no DNA samples is 16 per cent, but rises to 41 per cent with samples. The technology is also useful in reinvestigating unsolved cases.