SAN FRANCISCO (AP) — California Attorney General Kamala Harris said Thursday that her office was reviewing a new report that found most residential mortgages in foreclosure in San Francisco are missing documents or signatures or otherwise violate the law.

More than 80 percent of the loans examined at the order of San Francisco Assessor-Recorder Phil Ting contained such errors, according to the report.

"The allegations are deeply troubling and, sadly, no surprise to homeowners and law enforcement officials in California," Harris said.

While many of the errors were technical and related to paperwork, the problem shows the state needs to change its antiquated real estate regulations, Ting said.

"The whole process ... is absolutely, 100 percent broken and not working for any of us at this time," Ting said. "These rules were made for people who walked or rode their horse to the bank."

The review found that signatures of some original owners of loans were missing and that affidavits were not filed showing lenders had contacted borrowers to discuss their options 30 days before a mortgage default notice.

The review was conducted by Newport Beach-based Aequitas Compliance Solutions. The company looked at 382 of the city's 2,405 foreclosure sales between January 2009 and October 2011.

The report said it was possible that homeowners were accused of defaulting on loans that they had never agreed to in the first place, and were being foreclosed by lenders that didn't own the loans.

Harris walked away from the negotiating table in September during talks with banks about a nationwide settlement over foreclosure abuses. She said last week that California's share of the settlement agreement reached with Bank of America Corp., JPMorgan Chase & Co., Wells Fargo & Co., Citigroup Inc. and Ally Financial Inc. this month could be worth up to $18 billion to the state, one of the hardest hit by the foreclosure crisis.

The settlement included provisions that would allow her office to continue to pursue liability claims and possible criminal charges against mortgage trustees and other third parties, Harris said, including Mortgage Electronic Registration Systems Inc., a company that maintains databases for tracking the transfer of ownership of mortgages.

The San Francisco report said that in a majority of loans reviewed, the MERSCORP database conflicted with ownership information registered with the county recorder's office.

MERSCORP did not immediately return messages left after business hours.

Harris said she would introduce legislation this month to enact reforms that would bring stiffer penalties for violations such as those alleged in San Francisco.

San Francisco District Attorney George Gascon said he is awaiting documents from Ting's office to determine if crimes occurred. "Mortgage-related fraud is a top priority and my office will prosecute those who prey on vulnerable homeowners," Gascon said.

The results of the San Francisco audit may hint at broader problems with how foreclosures have been handled since the collapse of the housing market, real estate experts said.

Richard Green, director of the University of Southern California's Lusk Center for Real Estate, said he would like to see similar audits done in other California cities to confirm San Francisco is not an isolated case.

But considering the high rate of errors with foreclosures in the city, which suffered a comparatively mild downturn when the housing bubble burst, Green said he would not be surprised if the audit's findings foretold a broader problem.

"Mistakes happen. But it's the robustness of this happening. It's that it's happening over and over again," he said.