Twenty-seven people have been arrested in countrywide dawn raids in a crackdown on “ghost broking” - the sale of fake car insurance policies.
City of London Police said the raids follow months of investigation by its insurance fraud enforcement department (IFED).
The force said 28 warrants were executed in Leicestershire, London, Manchester, Thames Valley, and the West Midlands early this morning in an operation that involved 168 officers.
They were supported by colleagues from City of London's economic crime directorate, as well as officers from Greater Manchester, Leicestershire, Metropolitan, Thames Valley and West Midlands police forces.
Twenty-five people were arrested on suspicion of fraud by false representation, one on suspicion of burglary and another on suspicion of immigration offences.
Ghost brokers often target young drivers by offering cheap deals.
But anyone who buys one of their policies finds themselves driving without insurance, which could lead to their car being seized by police, fines, penalties and a criminal record.
Uninsured drivers also have to pick up the bill for any damage or injuries they cause in a crash.
City of London Police said its IFED has already brought to justice ghost brokers who tried to sell or sold cheap fake car insurance policies online, using phony websites as well as genuine classifieds and social media websites. The unit has also had reports of them approaching people in restaurants and internet cafes as well as on university campuses.
IFED head Detective Chief Inspector Dave Wood said: "This day of action reveals ghost broking to be a UK-wide problem which is being met by a national law enforcement response, led by IFED.
"The consequences for innocent motorists who fall victims to ghost brokers can be dire, so it is absolutely vital that drivers shopping for car insurance online, or through other means, question what they are being offered to ensure they get a real deal.
"Driver diligence, coupled with enforcement action being taken by IFED and supported by local forces, is the best way to confront this threat now and in the future."
The RAC today said it was particularly worrying that many people taken in by "ghost brokers" were those who could least afford the consequences of being involved in an accident without valid insurance.
Director of insurance services Kerry Michael said: "This is a new and worrying crime which preys on young drivers offering them cheap insurance rates with bogus policies.
"It is particularly worrying when you consider that many of the individuals taken in by 'ghost brokers' are those who can least afford the devastating financial and personal consequences of being involved in an accident without valid insurance.
"Whenever considering cover buyers are best advised to choose a reputable motor insurer and to ensure they check all of their paperwork. If a deal sounds too good to be true then it probably is."
The breakdown of arrests is:
Greater Manchester Police - 3
Leicestershire Police - 1
Metropolitan Police - 9
Thames Valley Police - 3
West Midlands Police - 11