Washington --

House Minority Leader Nancy Pelosi is the subject of a report on the stock investments of members of Congress that is to air Sunday on CBS' "60 Minutes."

The San Francisco Democrat and House Speaker John Boehner, R-Ohio, were questioned separately at their weekly news conferences Nov. 3 by reporter Steve Kroft. Neither had granted Kroft's previous requests for interviews.

Kroft asked both leaders about stock transactions they made while Congress was considering legislation that could affect the financial and insurance industries. Pelosi and Boehner vigorously denied any connection.

Laws against insider trading - making stock bets based on information the public doesn't have - do not apply to Congress. Studies have shown that stock portfolios on Capitol Hill outperform the market. Legislation that would ban insider trading by members and staffers has languished.

Kroft asked Pelosi why she and her investor husband, Paul Pelosi, bought an initial public offering of stock in Visa, the San Francisco-based credit card company, in March of 2008.

The same month, former House Judiciary Committee Chairman John Conyers, D-Mich., introduced the Credit Card Fair Fee Act, which would have given merchants the power to negotiate lower fees with credit card companies. The bill, hostile to the credit card industry, was passed by the committee but never brought to the floor. Pelosi was speaker at the time, and controlled which legislation came to a vote.

The Pelosis bought the Visa stock in three transactions totaling $1 million to $5 million, according to financial disclosure reports. The first was the IPO, followed by two other purchases of the stock at higher prices, Pelosi said.

Pelosi said the Conyers bill had no chance of being signed by then-President George W. Bush. She said she brought even tougher legislation, the Credit Cardholders' Bill of Rights by Rep. Carolyn Maloney, D-N.Y., to passage after President Obama took office.

Pelosi said the credit card industry spent $3 million in an unsuccessful attempt to defeat Maloney in 2010.

"First of all, what you are contending is not true," Pelosi said at her news briefing last week. "But second of all, we are very proud of our record of what happened."

Kroft asked what was untrue given that the Pelosis had bought the Visa stock two years earlier.

"Well, I have many investments ... I will hold my record in fighting the credit card companies, as a speaker of the House or as a member of Congress, up against anyone." Pelosi said. " We had passed the Credit Cardholders' Bill of Rights. I don't know what your point is."

Kroft then asked whether there was an appearance of a conflict of interest. "No, it only has the appearance if you decide that you are going to elaborate on a false premise," Pelosi said. "But it is not true, and that is that."

When Kroft said, "I don't understand what part is not true," Pelosi replied, "That I would act upon an investment."

Boehner has adviser

Boehner was asked at his news conference why he traded in insurance industry stock shortly before announcing that a plan for national health insurance was dead. Boehner said a financial adviser makes decisions on day-to-day trading in his investments.

The "60 Minutes" segment follows a flurry of stories about wrongdoing in Washington, including a segment on the program last week by disgraced former lobbyist Jack Abramoff, who served 3 1/2 years in prison for his 2006 conviction in a lobbying corruption scandal that helped bring down former House Majority Leader Tom DeLay, R-Texas.

Abramoff said he lavished gifts on members of Congress, offered lucrative jobs to their staff and got them to insert opaque legislative language into bills that benefited specific clients. Pelosi promised to "drain the swamp" in Washington when she took control. Abramoff asserted that reforms have been ineffective.

Pelosi's office said "60 Minutes" told her staff that the report was based on a book by conservative writer Peter Schweizer, a fellow at the Hoover Institution at Stanford University, who earlier had accused the Pelosis of hypocrisy for hiring non-union labor at their Napa vineyard.

Labor at the vineyard

A report at the time by ABC's San Francisco affiliate, KGO-TV, found that the Pelosis paid their workers more than union wages and that it would have been illegal for them to encourage unionization.

Several studies have shown that members of Congress and their staffs do better in the stock market than the public. A 2011 study by four university researchers found that a portfolio that mirrored stock purchases by House members from 1985 to 2001 beat the market by 6 percent a year. The same authors found that senators beat the market by 12.3 percent from 1993 to 1998.

The Wall Street Journal reported a year ago that in 2008 and 2009 at least 72 congressional aides traded shares of companies that their bosses helped oversee. The staff interviewed included a Pelosi aide who said her husband made the trades based on newspaper reports and that she knew nothing about them.

A bill by Reps. Louise Slaughter, D-N.Y., and Tim Walz, D-Minn. called the STOCK Act, or Stop Trading on Congressional Knowledge Act, would ban members of Congress and staff from insider trading. The legislation, which Pelosi supports, was first introduced in 2006 and has gone nowhere.