When Senator Kent Conrad of North Dakota wanted a mortgage for his beach house, he turned to a Washington insider, James A. Johnson, former head of Fannie Mae, the government mortgage giant, who then put the senator in touch with Angelo Mozilo, chief executive of the mortgage lender Countrywide Financial.

The ensuing telephone call between Mr. Conrad and Mr. Mozilo led to two Countrywide mortgages, including one in which the company bent its rules to give Mr. Conrad a loan.

Those loans are now among a number of Countrywide mortgages at the center of an examination into whether a number of top politicians in Washington — members of Congress, the cabinet and celebrated advisers — received favorable deals from a company whose lax lending standards are at the center of the subprime mortgage crisis.

This week, Mr. Johnson, whom Mr. Conrad turned to for help, was forced to step down as head of Senator Barack Obama’s vice-presidential selection committee in part over Countrywide home mortgage loans that Mr. Johnson had received at favorable rates.

At the center of the scrutiny is Countrywide’s “V.I.P.” program, also known as the “Friend of Angelo” program, in which Countrywide appeared to bend its lending rules for prominent people. Now, many of those receiving Countrywide home mortgages say they were not aware the company might have been working behind the scenes to give them favorable loan terms.

Senator Christopher J. Dodd of Connecticut, chairman of the Senate Banking Committee and a leader in the effort to help homeowners caught in the mortgage crisis, denied on Friday that he received preferential treatment for his two Countrywide loans. A spokesman for Mr. Dodd, Bryan DeAngelis, said that neither Mr. Dodd nor his wife had spoken to Mr. Mozilo about their loans.

“As a United States senator, I would never ask or expect to be treated differently than anyone else refinancing their home,” Mr. Dodd said in a statement. “This suggestion is outrageous and contrary to my entire career in public service. Just like millions of other Americans, we shopped around and received competitive rates.”

But Portfolio.com, the Web site of the business magazine Portfolio, cited internal documents indicating that Countrywide had reduced the rate on the mortgage of Mr. Dodd’s Washington town house by three-eighths of a point, saving him $2,000 a year in interest payments, and reduced the rate on a Connecticut house by a quarter point, saving $17,000 over the life of the loan.

For Mr. Dodd, who is said to be on a short list for vice president for Mr. Obama, the Countrywide mortgages may prove to be a problem in light of Mr. Obama’s ejection Mr. Johnson from his campaign over a similar issue.

“Obama has set such high standards on ethics,” said James Thurber, director of the Center for Congressional and Presidential Studies at American University in Washington. “If indeed Chris Dodd got below-market loans, it could be a disqualifier for someone being considered for an important appointment.”

In the case of Mr. Conrad, a member of the Senate Finance Committee, Portfolio.com cited Countrywide memorandums in which Mr. Mozilo told an employee to “make an exception due to the fact that the borrower is a senator.” That exception applied to a mortgage for an eight-unit apartment building in Bismarck, N.D., that Mr. Conrad was buying. Countywide normally provided mortgages for apartments with only four or fewer units.

For Mr. Conrad’s $1.07 million mortgage on his home in Bethany Beach, Del., Mr. Mozilo sent an e-mail message directing an employee to “take off 1 point,” or reduce the interest rate by a percentage point.

In an interview, Mr. Conrad said he was unaware of any special effort on his behalf and called his credit rating “spotless” in suggesting that he was eligible for favorable loan terms. He said he turned to Mr. Johnson and Mr. Mozilo because he was buying a property in Delaware and did not know where to get a mortgage in that state. After the phone call with Mr. Mozilo, a Countrywide loan officer called Mr. Conrad.

“I have a very high credit rating and that made me a pretty attractive customer,” said Mr. Conrad, who said he has had about 11 mortgages in his life. “I did not believe for a moment that I was getting preferential treatment. I thought I was getting good service from a real capable loan officer. I felt I was getting special treatment, but not that I was getting a special rate.”

Such loans to members of Congress or executive branch officials — if given on favorable terms — could run afoul of federal ethics laws that limit the amount public officials can receive as a gift, according to campaign ethics watchdogs. But if the senators were unaware that they were receiving favorable treatment and if there was no quid pro quo, it would be harder to make a case. Still, Citizens for Responsibility and Ethics in Washington, a nonprofit watchdog group, has called for Congressional ethics committees to investigate.

“There are legitimate questions that need to be answered,” said Melanie Sloan, executive director of the group. “It sounds like these senators didn’t inquire too closely about what they were getting.”

Portfolio.com reported that Alphonso Jackson, the former secretary of housing and urban development under President Bush; Donna E. Shalala, the secretary of health and human services under President Bill Clinton; and the former United Nations ambassador Richard C. Holbrooke also were part of the Countrywide V.I.P. program.

Richard Beattie, a lawyer for Mr. Holbrooke, said his client “personally had no contact with anybody at Countrywide and, to his knowledge, he got no favorable treatment.” Annette Herrera, a spokeswoman at the University of Miami, where Ms. Shalala is president, said Ms. Shalala was “not commenting on the issue at this time.”