The firm’s fraud report said 84 in every 10,000 mortgage cases had some form of fraud in the last quarter of 2014.

This was down from the 87 per 10,000 the previous year but remains the most vulnerable financial product.

Experian said mortgages were not usually targeted by identity thieves and that borrowers misrepresenting themselves were the main source of fraud.

Almost nine-in-ten cases (88%) of fraud were due to applicants making fraudulent claims to their bank, known as first party fraud.

Nick Mothershaw, UK&I director of identity & fraud at Experian, said: “Lenders continue to make significant strides in the fight against fraud and safeguarding their customers – particularly against identity theft.

“But as more consumers access and apply for financial products across multiple channels, including online and mobile, fraud has also evolved accordingly.”

Across all financial services the level of first party fraud dropped to 48% of all cases. This was due to a rise in identity theft and similar fraud in the last 12 months.

“More fraud is being spotted thanks to the vigilance, diligence and determination of the financial services sector,” Mothershaw added.

“But are other external factors are now coming into play? Stricter affordability tests, while playing a clear role in protecting individuals from unmanageable debt, have made the process of switching mortgages more complicated and lengthy.  It may be possible that they are prompting some applicants to falsify their credit commitments, earnings, or job status.”