Some crash for cash fraudsters are behaving like "highway robbers" and demanding money from their victims at the scene of an accident - in a new twist on the scam.
Criminals who stage a crash for cash motor accident will often slam on their brakes without warning so that the victim driving behind them has no choice but to slam into them.
Traditionally, fraudsters will then go on to make an insurance claim which they will bump up with bogus injuries such as whiplash.
But in a new version of the scam, fraudsters are also pressuring victims at the scene into handing over cash.
In one case seen by an insurer, a motorist was offered a lift to a cash machine in order to get some money.
The elderly, women travelling alone or with children, and younger, more inexperienced drivers could be particularly at risk, it is feared.
High-value cars, which are more likely to be insured, also tend to be targeted by crash for cash fraudsters.
Tom Gardiner, head of fraud at Aviva, described the new trend as "bringing back the days of 'highway robbery'".
He said: "Although it is early days, we are seeing anecdotal evidence of fraudsters deliberately causing an accident and then pressuring the target - or 'at fault' party - into paying them money in exchange for not making an insurance claim.
"We have even seen an example where the third party said he would drive our customer to a cash machine in order to get the money."
Mr Gardiner said: "Motorists are left feeling intimidated and that they have no choice to comply."
He said that if someone feels threatened following an accident they should call the police to attend the scene.
Drivers should not make any admission of fault or payment, but simply make a note of the other party's registration number, and get as much information as possible, such as name, address, phone number and the number of people in their vehicle, he said.
Mr Gardiner added: "If possible and safe to do so, take a photo of the accident.
"You should tell your insurer about the other party's behaviour so they can investigate the claim and defend you if it is fraudulent."
If a driver suspects an accident was staged, they can report it to the Insurance Fraud Bureau's (IFB) cheatline on 0800 422 0421.
Ben Fletcher, director of the IFB, told the Press Association that scam victims should not assume that paying up at the scene of a crash would put an end to the matter.
The gangs behind this type of crime are well-organised and will pay a stooge to drive the car involved in the crash.
Even if the victim pays up, it is likely that the stooge will pocket the cash and the gang will still go on to make a bogus insurance claim, which if successful is likely to be more lucrative for them than whatever money they can get at the roadside, he said.
Mr Fletcher said: "We have seen examples where they have tried to ask for cash at the scene and they have still gone on to make a claim through the insurance company."
He said that if someone does pay up at the scene, all they will be doing is increasing the potential earnings from the scam for the criminal.
Another give away sign of a crash being bogus is if the driver of the other vehicle appears unusually calm for someone who has just been involved in an accident, he said.
Mr Fletcher said drivers involved in an accident should tell their insurer.