The number of 'crash for-cash' car insurance scams uncovered by a major insurer surged by 51% annually last year.

Aviva said it had detected about 820 staged accidents in 2013, leading to some 2,200 fraudulent personal injury claims.

It is pressing for tougher penalties and said that often, rather than being locked up, fraudsters ended up being sentenced to community orders, which 'do little' to deter them from offending again.

Aviva, which insures about one in 10 cars in the UK, said that organised gangs were behind half of all the fake motor injury claims it uncovered.

It suggested that growing industry-wide efforts to weed out bogus whiplash claims which drive up the cost of insurance could be prompting criminals who may have previously completely fabricated a 'ghost' accident which never actually happened at all to instead stage a crash for cash induced accident, in a bid to produce more 'evidence' to back up a claim.

Often, innocent motorists get caught up in crash for cash incidents. Usually, in road traffic accidents where one vehicle is hit from behind by another, it is the driver of the car behind who is deemed to be at fault. So, in a crash for cash incident, a car may brake suddenly in front of the innocent victim, leaving them with little chance but to run into the back of them.

There have also been reports of fraudsters disconnecting their brake lights so that the car behind has even less chance of stopping.

Gangs tend to target innocent drivers who appear the most likely to be insured and the least likely to kick up a fuss, such as those with well-maintained cars, older drivers and families with young children.

As well as the risk of physical injury to innocent victims, crash for cash cases also pump up the costs for all drivers through higher premiums. According to industry estimates, frauds of all types add around £50 to the cost of a typical insurance premium.

Tom Gardiner, head of claims fraud at Aviva, said: 'The fast growth of induced accidents on our roads is cause for serious concern.

'Fraudsters are prepared to put the safety of innocent motorists and their families and passengers at risk for their own personal gain.'

Aviva said that as well as maintaining a safe distance behind the driver in front, motorists should be particularly cautious if they notice that the brake lights on the car in front are not working.

If the driver in front appears to be focusing on the back of their vehicle, this could be a sign they are looking for an opportunity to induce an accident.

If someone suspects they have been the victim of a crash for cash scam, they should call the police while they are still at the scene and ask them to attend, the insurer said.