From the boulevards of Paris to the beaches of Puerto Rico, members of Congress -- Democrat and Republican -- have taken more than $16 million in trips paid by private sources in the last five years, according to a report released by PoliticalMoneyLine, an independent research group.
At the top of the list, at least monetarily, sits Rep. James Sensenbrenner, R-Wis., who has taken $167,000 worth of trips.
"Some of them serve a legitimate purpose," said Fred Wertheimer, president of Democracy 21, a government watchdog organization. "Too many of them are simply excuses for people to take vacation-type trips paid by groups that lobby Congress."
Among those whose trips are now being scrutinized is House Ethics Committee member Stephanie Tubbs Jones, a Democrat from Ohio.
According to House disclosure forms Jones filed after a free trip she took with her husband to Puerto Rico four years ago, a Washington lobbying firm, Smith Dawson & Andrews, paid the $3,366 bill, a violation of House ethics rules.
Late last week, Jones quietly changed her disclosure report, removing the name of the lobbying firm and replacing it with a non-profit group in Puerto Rico, which can pay for such travel under House rules.
Jones attributed it to human error but refused to be interviewed.
James Smith, managing director for Smith Dawson & Andrews told ABC News, "Smith Dawson & Andrews was not a sponsor of Congresswoman Stephanie Tubbs Jones' trip to Vieques, Puerto Rico, nor did the firm pay for any costs associated with any of the congressional visits."
At least seven members of Congress or their staff have recently amended their disclosure forms, including the office of Republican Majority Leader Tom DeLay.
A spokesman for DeLay said that they were in the process of carefully examining trips taken by DeLay and staff members.
The ethics issue is a Republican one, according to the Democratic leader of the House, Rep. Nancy Pelosi of California.
"Let me just make one statement about the Republicans," she said at a press conference last October. "Their greed will be their downfall. Anyone who has a critical eye about what is appropriate behavior will know that there is abuse of power here. There is behavior that borders on corruption."
But documents obtained by ABC News reveal problems in Pelosi's office as well.
An internal review undertaken by Pelosi's office found that members of her staff took 41 free trips over the last three years, 12 of them not properly disclosed.
Some Republicans felt the Democrats were guilty of a political double-standard.
"It's the pot calling the kettle black," said Rep. Patrick McHenry, R-N.C. "They call their own failure to disclose travel a mere oversight but when Republicans do it they call it a first-rate scandal."
Congress changed its ethics rules for travel 10 years ago following a series of ABC News reports that caught lobbyists and congressmen partying together in island getaways such as Barbados and Captiva Island.
But reformers say more changes are needed.
"Ethics rules were strengthened in the 1990s but they left loopholes for travel and those have been exploited," Wertheimer said.
Now on Capitol Hill, lobbyists say members are afraid to take any free trips, legal or not.
"This doesn't look good for us back home, doesn't look good for us here in Washington, so we're not going to do it," said Paul Miller, president of the American League of Lobbyists. "I think it has caused people to panic a little bit."
Rhonda Schwartz, Jill Rackmill, Avni Patel and Jessica Wang contributed to this report.