As leaders of two Realtor associations prepare to launch a task force on fraud today, agents and others in the industry say recent publicity and the threat of prosecution have iced some shady real estate operations, while driving others underground.

The California Department of Real Estate recently revoked the license of one mortgage broker whose clients bought multiple houses with full financing, and then let them fall into foreclosure. The department also has opened an investigation in connection with another real estate agent similarly tied to at least 56 foreclosures, according to a home appraiser who advised the department.

Several similar but smaller groups appear to have curtailed their activities and others have disappeared altogether, according to two local appraisers who have followed the groups.

That's partly because mortgage lenders -- at least those that remain in business -- have created "blacklists" of mortgage brokers whom they suspect of orchestrating fraudulent loan applications, said Todd Lackner, a San Diego appraiser who has advised state and local law enforcement agencies investigating potential real estate fraud in Southwest County. And some title companies have become wary of certain real estate agents, Lackner said.

Most notably, questionable investment groups have begun to avoid the Multi-Regional Multiple Listing Service, a database used by most local real estate agents. That move allows the investor groups to escape attention but it also limits the number of houses they can buy and sell, according to agents and appraisers who have followed their activities.

"The MLS boards are hammering down on it and the government agencies are watching them," Lackner said.

Several leaders in the real estate industry, however, say they are dismayed that law enforcers haven't done more to prosecute cases of apparent fraud.

The anti-fraud task force, expected to convene for the first time today, aims to put pressure on law enforcement agencies, some of its members say. The task force includes leaders of Realtor associations whose members do business in Southwest County and the Riverside-San Bernardino area, the associations' attorney and possibly a representative of the Multi-Regional Multiple Listing Service.

The Southwest Riverside County Association of Realtors reported one particularly large series of suspicious house purchases to law enforcement agencies in late 2004 or early 2005, said John Giardinelli, a Canyon Lake attorney who advises both Realtor associations. Giardinelli's office has since compiled a file of suspicious transactions in a binder several inches thick.

Gene Wunderlich, chairman-elect for the Southwest County association, said local agents have become increasingly wary of buyers whose agents insist on large cash kickbacks for buyers, a common feature among the deals the Department of Real Estate has investigated. But Wunderlich and other agents have often noted that an agent listing a house is obligated to inform her clients, the would-be sellers, of all offers regardless of their source.

But by meeting regularly to discuss suspicious transactions, leaders of the real estate associations will be able to identify patterns more quickly and more effectively and pass the information on to authorities, members of the task force said.

The initiative comes amid an unprecedented wave of foreclosures that threatens to swamp housing markets in outlying suburbs that were booming just three years ago. Lowered lending standards helped hundreds of thousands of families buy homes, but they also drew shady investment groups that hoped to make easy money in the market frenzy, according to real estate professionals.

Such investment groups may have helped to drive prices higher in 2004 and 2005, helping to put extra money in the pockets of ordinary sellers at the time, appraisers said in recent weeks. But they're also intensifying the housing hangover of 2007, with a large pool of sellers having to compete for a limited number of buyers, the appraisers say.

In Southwest County, about 5,000 houses are in the foreclosure process, according to foreclosureradar.com.

Real estate agents have said they're concerned that the rash of foreclosures has many potential buyers sitting on the fence until prices fall further, a situation that makes selling a house even more difficult. Fraudulent sales have become a particular target of frustration, Giardinelli said.

"The Realtors sense that they're being affected to the extent that this strike force has become a necessity," he said.

Contact staff writer Chris Bagley at (951) 676-4315, Ext. 2615, or cbagley@californian.com.