So-called “jingle mail,” when busted homeowners give up and mail in the keys, isn't the only problem with home mortgage loans.

Now banks are walking away from the very properties on which they have foreclosed because the value has plummeted or the bank believes the home could become a costly liability due to housing code violations.

These so-called "bank walkaways" are another troubling development in the foreclosure crisis, particularly in weaker housing markets, say housing advocates and government officials.

Without a sale, property can languish, abandoned, and ripe for vandalism. As liens and liabilities mount — creating what’s known as a "toxic title" — it becomes even harder to transfer the property.

Neighborhoods and local governments are left to deal with the mess.

Joseph Schilling, associate director of the Metropolitan Institute at Virginia Tech and an expert on abandoned property, said the issue of bank walkaways is increasing as lenders decide that, given low prices and their mounting inventory of foreclosed property, it makes sense to walk away.

"But as a result, it leaves the property in this type of legal limbo and it leaves the community and local government really holding the bag," Schilling told The Cleveland Plain Dealer.

National foreclosure filings in the U.S. continue to shatter records, propelled by mounting unemployment and continued erosion of home values, The Wall Street Journal reports.

Filings were reported on more than 336,000 properties in June, the fourth straight month to see the total topping 300,000, helping to boost the second-quarter's tally by 20 percent from the year-earlier period.

During the first half of this year, one in every 84 homes was slapped with at least one filing, ranging from default notices to bank repossessions.