WASHINGTON — Billions of dollars the government is spending to help financially pressed homeowners avert foreclosure are passing through — and enriching — companies accused of preying on the people they're supposed to help, an Associated Press investigation has found.

The companies, known as mortgage servicers, are middlemen who collect monthly payments from homeowners and funnel the money to the banks or investors who hold the loans. As the only link between borrowers and lenders, they're in the best position to rework the terms of loans under the government's $50 billion mortgage-modification program. The servicers are paid by the government if the changes keep homeowners from falling behind on payments for at least three months.

But the industry has a checkered history. The AP found that at least 30 servicers have been accused in lawsuits of harassing borrowers, imposing illegal fees and charging for unnecessary insurance policies. More recently, the companies also have been criticized for not helping homeowners quickly enough — delays that lead to more fees for homeowners and profits for servicers.

The biggest players in the servicing industry — Bank of America, Wells Fargo & Co., JPMorgan Chase & Co. and Citigroup Inc. — all face litigation, some of which has led to settlements with homeowners. All will receive federal money to modify loans.

But the industry's smaller players, which specialize in servicing riskier subprime loans and loans already in default, face harsher accusations that they systematically abused borrowers.

"The irony is, in essence, the government is paying servicers to do their job, which is to do loan modifications where appropriate," said Kurt Eggert, a law professor at Chapman University in Orange, Calif. "And that's not a part of their job they were ever especially good at."

The government says it has no choice but to partner with the servicers because they are the only link between borrowers and the investors who indirectly own their mortgages through securities.

When President Obama announced the plan, called the Home Affordable Modification Program, in March, he said it would help up to 4 million homeowners avoid foreclosure. But only about 200,000 loan modifications are under way. Last week, 25 mortgage-servicing executives were summoned to the Treasury Department for meetings at which they promised to deliver 300,000 more loan modifications by Nov. 1.

Under the loan-modification program, 38 servicers will earn fees to help reduce the monthly payments of homeowners facing foreclosure. The goal is to modify mortgages so homeowners' payments don't exceed 38 percent of their gross monthly income.

Without government aid, servicers don't have enough financial incentive to modify mortgages. Each year, they earn about one-quarter to one-half percent of the value of the loans they service, so the larger the mortgage, the more they make. The servicers also make money through late fees, or by foreclosing.

Under the Treasury program, the servicers could pocket more than $5,500 for each loan they modify. But they aren't paid until the homeowners make timely payments for three months. The servicers will also get government money to give to mortgage investors to compensate them for reducing the loans. How much will depend on what it costs the investors to modify the loan.

The largest mortgage servicing abuse lawsuit was brought against Select Portfolio Servicing, which was accused of imposing illegal fees and charging borrowers for insurance they did not need.

The company paid $55 million in 2003 to settle charges brought by the Department of Housing and Urban Development and the Federal Trade Commission. It is eligible for up to $660 million under the Obama plan — some to keep and some to pass on to investors and homeowners.

For six years, Jerry Turner made payments to Select Portfolio for a Charleston, W.Va., house he no longer owned.

In 2000, Turner was promised a loan modification in a court settlement. His mortgage belonged to a bank-owned pool of loans eventually serviced by Select Portfolio. Instead of lowering Turner's payments, the bank foreclosed on Turner's home, court documents show. The bank then took the house back at auction.

Select Portfolio never told Turner his house had been sold. It continued sending him monthly invoices and cashing his checks. He didn't find out he had lost the house until it was sold a second time, at auction — because Select Portfolio hadn't paid property taxes on the home.

"I had excellent credit at one time," Turner said. "Now, I can't borrow money on the house, I can't leave it, and it's been tied up so much I don't know what to do."

Turner's case against Select Portfolio is pending in West Virginia state court.

Treasury says it has no choice but to work with all servicers, no matter how dubious their records. Refusing to work with a particularly bad player would "deprive homeowners who have mortgages with that servicer from getting modifications," Treasury spokeswoman Jenni Engebretsen said in a statement.

An AP analysis of the 38 servicers the government is paying to help vulnerable homeowners found that at least 30 face lawsuits from homeowners and advocates claiming they charged illegally high fees, prematurely foreclosed on homes and engaged in illegal collection practices.