WASHINGTON - Top federal and state officials on Monday announced a broad crackdown on mortgage modification scams, accusing "criminal actors" of preying on desperate borrowers caught up in the nation's housing crisis.

Government officials say scammers are trying to take advantage of borrowers in danger of default by charging them upfront fees of $1,000 to $3,000 for help with loan modifications that rarely, if ever, pay off.

The frauds often involve companies with official-sounding names designed to make borrowers think they are part of the Obama administration's efforts to help modify or refinance 7 million to 9 million mortgages.

Officials say such operations almost always are fraudulent, and that help is available for free from government-approved housing counselors.

A new Florida law prohibits mortgage rescue companies from requiring upfront fees and other such business practices.

"These predatory scams callously rob Americans of their savings and potentially their homes," Treasury Secretary Timothy Geithner said. "We will shut down fraudulent companies more quickly than before. We will target companies that otherwise would have gone unnoticed under the radar."

The Federal Trade Commission has sent warning letters to 71 companies it says were running suspicious advertisements. The agency also said it filed three new complaints against Northridge, Calif.-based Federal Loan Modification Law Center LLP, Newport Beach, Calif.-based Bailout.hud-gov.us, and Clearwater-based Home Assure LLC, and the operators of those companies.

Homeowners do not have to pay anything to participate in the administration's Making Home Affordable program, which seeks to prevent foreclosures by making mortgages affordable through refinancing or modified terms.

LEGITIMATE HELP

Homeowners can locate free housing counselors by calling (888) 995-HOPE or at www.makinghomeaffordable.gov.