Arthur Laupus joined AARP because he thought the nonprofit senior-citizen-advocacy group would make his retirement years easier. He signed up for an auto insurance policy endorsed by AARP, believing the advertising that said he would save money.

He didn't. When Laupus, 71, compared his car insurance rate with a dozen other companies, he found he was paying twice the average. Why? One reason, he learned, was because AARP was taking a cut out of his premium before sending the money to Hartford Financial Services Group, the provider of the coverage.

Laupus stumbled onto something that many members of the world's largest seniors' organization don't know: The group, formerly called American Association of Retired Persons, collects hundreds of millions of dollars annually from insurers who pay for AARP's endorsement of their policies.

The insurance companies build the cost of these so-called royalties and fees, which amounted to $497.6 million in 2007, into the premiums they charge AARP members, according to AARP's consolidated financial statement for that year.

AARP uses the royalties and fees to fund about half the expenses that pay for activities such as publishing brochures about health care and consumer fraud -- as well as for paying down the $200 million bond debt that funded the association's marble and brass-studded Washington headquarters.

In addition, AARP holds clients' insurance premiums for as long as a month and invests the money, which added $40.4 million to its revenue in 2007.

"At the end of the day, it's all about fattening the coffers of the organization," says Thomas Orecchio, who was chairman of the Arlington Heights, Ill.-based National Association of Personal Financial Advisors until September. AARP, he says, is sponsoring insurance for its members at inflated prices.

"It's the dirty little secret," he says.

During the past decade, royalties and fees have made up an increasing percentage of AARP's income, rising to 43 percent of its $1.17 billion in revenue in 2007 from 11 percent in 1999, according to AARP data.

With stock markets around the world plunging, savings plans in turmoil and medical costs soaring, older Americans need an advocacy organization in their corner.

Iowa Republican Sen. Charles Grassley sent letters to AARP Chief Executive Officer William Novelli and state insurance commissioners Nov. 3 inquiring into whether the AARP misrepresented what is covered by some health insurance policies it sold. Four days later, Novelli announced AARP would review its marketing and suspend sales of those policies.

AARP's mission to help seniors has been compromised by its reliance on royalties and fees, says Marilyn Moon, who was director of AARP's Public Policy Institute from 1986 through 1989.

"There's an inherent conflict of interest," she says. "A lot of people there are trying to do good, but they're ending up becoming very dependent on sources of income."