WASHINGTON — The Federal Housing Administration will prohibit borrowers from using seller-financed down-payment assistance programs that have helped hundreds of thousands of people buy homes but have come under the scrutiny of federal authorities.

Such programs allow home sellers to give money to charities, which then give down-payment assistance to buyers. The sellers pay the charities a service fee, then often recoup the money by charging a higher price for the homes, usually 2 or 3 percent more, or an amount equal to the down payment, according to a study by the Government Accountability Office.

In a conference call with reporters, Federal Housing Commissioner Brian Montgomery said that the FHA will publish its new rule in the Federal Register on Monday. The rule, which is little changed from a preliminary version put out for comments in May, will go into effect 30 days after publication.

"These contributions often function as an incentive to purchase the home," Montgomery said. "But these gifts are ultimately paid for by the borrower through a higher mortgage amount. The home buyers are often unaware that the 'gift' is something they end up paying for and is not a 'gift' at all."

Almost 200 charities nationwide have participated in such arrangements. But the IRS and other government entities have raised concerns, particularly after the 2005 GAO study found that borrowers receiving assistance from the charities were more than twice as likely to default or become delinquent than other FHA borrowers were.

In a ruling last year, the IRS went so far as to call the seller-financed programs "scams," accusing the charities of inflating home prices.

Ann Ashburn, president of AmeriDream, criticized the FHA rule and said there is no evidence that down-payment programs raise prices.

The housing market has deteriorated so much that home prices cannot be inflated, she said. "At the end of the day, the buyer has the ultimate say," she said.

Borrowers of FHA-insured loans will still be able to get down-payment assistance from family, employers, governmental entities or charitable organizations.