Insurance executives believe unscrupulous claims management firms, lawyers and doctors have discovered loopholes in new laws that were designed to end the scandal.
They said criminal outfits had returned to cold-calling susceptible members of the public and convincing them to fake injuries in front of doctors.
Data obtained by The Telegraph suggest 7,500 more whiplash claims are being submitted each month than last year – yet the number of road accidents has remained almost unchanged.
On Monday one of Britain's biggest car insurers, Esure, said its profits had fallen by a fifth as a result of the surge. It said it planned to increase premiums for all drivers to "mitigate against" the higher costs.
David Williams, managing director of Axa, another major insurer, said:
"We are seeing bigger and more fraudulent claims as companies find ways round the rules. It's as bad, if not worse, than before."
Annual car insurance premiums are now rising for the first time in three years as insurers struggle to cope with the return of whiplash fraudsters, according to the AA.
The "10 to 15 per cent" increase it predicts for the year would add around £80 to the cost of a new annual car insurance policy, which now averages around £550.
Premiums had hit £715 a year before they began to fall steadily when the Government introduced measures to tackle the Britain's "compensation culture" in 2013.
Since then there has been a ban on "referral fees" paid between lawyers, insurers, claims firms for potential clients; medical professionals have been blocked from charging more than £180 for preparing whiplash injury reports; lawyers have had charges capped at £500 for preparing a basic claim; and all claims must now be verified by a randomly-selected medical expert before they are looked at by the insurance company.
Following the reforms the annual cost to insurers of processing personal injury claims and issuing payouts fell by a third.
But the experts now believe disreputable claims firms were merely pausing to work out how to circumvent the restrictions.
Mr Williams, of Axa, said: "There was a bit of panic [in the claims industry] until the realisation that the Government's changes weren't as dramatic as people thought and money could still be made.
"In the early days after the reforms claims firms didn't know what they could get away with, but now they have established a number of ways around the rules."
The monthly total for personal injury claims dropped below 60,000 in June 2013 after the new rules were introduced, data collected by the Ministry of Justice show.
Now 73,500 a month are now being submitted on average, up from 66,000 last year.
Claims firms and lawyers are believed to be circumventing the ban on referral fees by asking clients to call carefully-selected partner firms, rather than passing names and telephone numbers between themselves.
Payment for this indirect referral is then made through an alternative, seemingly legal, route.
Some companies are thought to be submitting multiple claims for each whiplash case to increase the chances of their client being allocated a doctor with which the company has a relationship.
Stephen Gaywood, insurance counter-fraud director for the AA, said attempts by the Ministry of Justice to stop cold calling were failing.
"The rules are being openly flouted. These firms are getting hold of customer data from somewhere and it’s not from insurers.
I have no doubt that their pushy tactics lead many people to make claims that they otherwise wouldn’t even consider."
In a poll of more than 24,000 people by researchers Populus and the AA, 11 per cent of respondents said they saw "nothing wrong" with making a claim for injury, even if no injury was suffered.
"Many legitimate collisions are vastly inflated by injury claims that are extremely difficult to disprove, so the balance of probability in a court would fall in favour of the claimant."