SACRAMENTO (KCBS) – A report by the California Attorney General’s office finds only 51 percent of the donations collected by professional fundraisers winds up in the hands of the charity soliciting contributions.

The report issued by Attorney General Kamala Harris shows a little more than half of the $339 million raised in California by professional fundraising operations during 2011 made it to the actual charities.

READ MORE: DEA Issues Safety Alert As San Francisco Fentanyl Seizures Soar

The cost of fundraising activities should not exceed 10 percent of donations received, said Ken Berger, president of Charity Navigator, a New Jersey company that evaluates how charities operate.

KCBS’ Barbara Taylor Reports:

“The problem is that we implicitly assume that most charities are good,” Berger said. “We don’t use our head, and we don’t do a little bit of research. We just go from the heart.”

READ MORE: Palo Alto Parking Garage Vandalized With Hate Graffiti For 2nd Time In 2 Weeks

Berger said high overhead costs can seriously undermine public trust in a non-profit organization over the long-term.

“Charities provide a variety of rationales for this. But on balance, none of them suffice and don’t satisfy the donors’ concerns about being misled and ripped off.”

Professional fundraisers are required to file annual disclosure reports with the state Attorney General’s office, whether they work for an independent company or are employed directly by the charity.

MORE NEWS: Mount Diablo High School In Concord Briefly Locked Down After Student Found With Gun Magazine

(Copyright 2012 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)