The risk of mortgage fraud related to property valuation is up 46 percent, compared to a year ago, according to data released Tuesday by Interthinx.

The California-based company’s study documents a considerable shift toward schemes involving short sales, REO inventories, and refinancing by borrowers whose equity has been impaired by falling real estate values.

Overall, the Interthinx Mortgage Fraud Risk Index, covering the most common types of mortgage fraud including property valuation, surged more than 11 percent from the previous quarter, indicating that fraud and its perpetrators proliferate during times of economic crisis and prey on desperate circumstances.

According to Interthinx, states with the highest levels of mortgage fraud risk correspond closely to the states with the highest levels of foreclosure activity, but the most striking trend over the past year, the company says, is the increasing geographic concentration of mortgage fraud risk.

Despite relatively small variations on the national scale, the range from the lowest to the highest risk state has widened considerably, Interthinx explained. Thus the riskiest states are now much more risky than a year ago and the least risky states are much less risky than a year ago.

Nevada continues to have the highest mortgage fraud risk, Interthinx said, but as DSNews.com reported earlier this month, the state has launched an all-out offensive to absolve that title.

California, another foreclosure hot spot, contains seven of the 10 riskiest metro areas when it comes to fraud potential, Interthinx said. The Golden State’s fraud index represents the largest one-year increase of all the states. Interthinx noted, though, that the highest risk counties were previously confined to the state’s inland region but the risk has now spread to many coastal counties as well.

Arizona and Florida rank third and fourth on Interthinx’s “riskiest” list – also among the states with the highest foreclosure rates.

New entries in Interthinx’s very high risk category included Charleston, South Carolina; Portland and Bend, Oregon; Minneapolis-St. Paul, Minnesota; and Washington D.C.

The company’s Occupancy Fraud Risk Index, which is closely correlated to schemes involving speculative investments, declined 30 percent from a year ago. Interthinx concluded that the drop was due to consumers’ reduced economic circumstances and the generally depressed market for residential investment and rental properties. However, a very slight increase over the last quarter – the first since the fourth quarter of 2006 – suggests that occupancy fraud risk may be poised for a rebound, Interthinx said.

The risk of fraud involving employment and income claims also declined – down 35 percent from this time last year. Interthinx attributes the decrease to lenders’ growing use of Internal Revenue Service data to verify income and to a reduced need for misrepresentation of income as housing generally becomes more affordable.

Interthinx analysts expect fraud risk to continue to rise over the next three years as a wave of adjustable-rate mortgage loans (ARMs) – especially option-ARMs – reset between now and the first quarter of 2012. The company also projects that while interest rates remain low, the predominant fraud type will continue to be related to property valuation as consumers attempt to refinance their mortgages despite reduced equity in their properties.