In May 2013, Richard Lugar, former U.S. senator and onetime chairman of the Senate Committee on Foreign Relations, took the podium at a sleek, modern convention center in the capital of Azerbaijan and urged the U.S. Congress to exempt a natural gas field in the Caspian Sea from economic sanctions against Iran.

The Baku conference was sponsored in part by SOCAR, the Azeri national oil company, and the vast Shah Deniz gas field was a potential game-changer in the country's quest to become a major player in global energy circles.

But one of SOCAR's partners in the Shah Deniz project was the Iranian national oil company, NIOC, and Congress was considering a new round of sanctions against Iran, Azerbaijan's neighbor, that could potentially derail a $28 billion project.

The Azeris, SOCAR and other major energy partners in the Shah Deniz project desperately wanted an exemption.

Ten congressmen and 35 staffers accepted all- expense-paid trips to the Baku conference. In Lugar's audience that day were three members of the U.S. House of Representatives who sit on the House Foreign Affairs committee considering Iranian sanctions - Texas Reps. Steve Stockman and Ted Poe, both Republicans; and Gregory Meeks, D-N.Y.

Less than two months later, the day before the House vote, the Shah Deniz exemption mysteriously appeared in the final draft of the sanctions bill, which passed.

It's unclear who engineered that last-minute change.

Ethics rules at issue

A Houston Chronicle analysis of reports that Stockman, Poe, Meeks and the seven other U.S. lawmakers later filed with the House Ethics Committee show that none disclosed any sponsorship of their Baku conference trips by corporations, foreign governments or lobbyists. Taking a foreign trip to a conference sponsored by corporations that employ lobbyists appears to be a violation of congressional ethics rules, according to the House ethics manual.

Only five of the 10 American lawmakers who made the Baku trip agreed to respond to the Chronicle's questions and said they complied with disclosure requirements.

The 2013 conference, called "U.S.-Azerbaijan: Vision for Future," was held at the Heydar Aliyev Center in Baku, a gleaming white architectural masterpiece by the Caspian Sea that, though named for a despot, serves as a symbol of Azerbaijan's transformation from former Soviet-bloc state to an energy-rich political player.

SOCAR, along with other Azeri government interests, has become one of Washington, D.C.'s big spenders in efforts to win American allies to get its petroleum products to markets worldwide.

Public records, programs, photos, emails and interviews collected by the Chronicle confirm that lobbyists, the Azeri government and energy companies all participated in the elaborate Baku gathering.

In addition to the 10 U.S. House members and staffers, state legislators and local politicians accepted all-expense-paid trips to the conference, which was festooned with the logos of SOCAR's powerful energy allies, including BP and ConocoPhillips.

Along with Stockman and Poe, Texas lawmakers Sheila Jackson Lee and Ruben Hinojosa, both Democrats, made the trip.

At least four congressmen took along a spouse or fiancé. Some flew first-class and extended their trips with stays in luxury hotels in Turkey. The congressional travel tabs alone totaled $270,000, trip reports compiled by the Chronicle show. That doesn't include fees or expenses paid to former government officials, like Lugar, who attended as speakers. He declined an interview request.

And according to documents, those bills were covered by five related, U.S.-based Turkic nonprofit organizations, one of which, the Turquoise Council of Americans and Eurasians, is based in Houston and described itself as the event's "organizer."

Under federal law, the Turquoise Council was required to disclose any corporate support or foreign government assistance for the Baku congressional trips. The Chronicle's analysis indicates it did not.

Scandals led to reforms

Scandals involving jaunts enjoyed by lawmakers to Caribbean islands and lavish European golf outings prompted the House of Representatives in 2008 to approve reforms that banned lobbyists and corporations that employ U.S. lobbyists from planning or funding foreign trips.

But foreign governments or corporations can still donate to nonprofits that give foreign trips to congressmen - a loophole that has created a boom in nonprofit-funded trips - provided both the nonprofits and the lawmakers disclose such support.

"Knowing the sponsors of these fact-finding trips gives voters the opportunity to hold their representatives accountable for any improper relationships. Without transparency there is no accountability," said Benjamin Freeman, a senior policy adviser at the nonpartisan Third Way in Washington, D.C. "How often does this happen? The honest answer is that we have no idea, because we don't know who many of these sponsors are. That must change."

The Baku conference, the marquee event of the congressional trips, featured a speech from Azerbaijan's president, Ilham Aliyev, whose family controls much of his country's wealth, and focused on Azerbaijan's political and energy agenda. It enjoyed substantial corporate support, including sponsorships from BP, ConocoPhillips and Caspian Drilling, as well as from SOCAR itself.

Energy giant BP confirmed with the Chronicle that it contributed $10,000 for the convention and gave more again this year for a follow-up event in Washington.

In an email, Houston-based organizer Kemal Oksuz said the Turquoise Council received $10,000 from various sponsors for the Baku conference, whose names appeared on the conference website. But Oksuz did not disclose that in travel forms he filed for congressmen who accepted funding from his group. Oksuz said he did not have to disclose corporate sponsorships, in part, because "those contributions always came after the conventions."

Nondisclosures illegal

Lawmakers who went to Baku and nonprofits alike should have disclosed any corporate conference sponsorships, said Ken Boehm, an expert in congressional ethics who reviewed the records at the Chronicle's request.

By failing to do so, even after seeing event banners and websites listing sponsors, congressmen may have violated ethics rules, he said.

Leaders of nonprofits that organized trips to Baku may have violated federal law by failing to disclose corporate sponsors, said Boehm, chairman of the National Legal and Policy Center, a nonprofit that promotes ethics in government.

"Once the corporate sponsors admit their paid involvement, it's game over for whoever signed the House pre-trip forms stating falsely that there was no such sponsorship," he said.

To pass muster, congressional "fact-finding" trips abroad must be organized principally for education purposes. Congressional officials must first ask the House Ethics Committee for permission to go, and sponsors must affirm that lobbyists will neither be involved in planning nor accompany House members on the trip.

Nonprofits sponsoring trips must disclose support from corporations or foreign agents. And, once they return to the United States, lawmakers must report true sponsors of trips to the best of their knowledge.

Records show that Meeks did not disclose his Baku trip expenses until a year after the deadline. Meeks did not respond to a request for comment.

Congressman Poe and two other Houston-area House members - Stockman and Jackson Lee - spoke at the conference in Baku at the invitation of the Turquoise Council. All three took flights that cost from $10,500 to $12,000, more than the current advertised first-class fares. Stockman got another $5,000 in campaign contributions in three installments that same month from Oksuz personally.

Neither Stockman nor Jackson Lee responded to any questions.

Poe said all trip expenses were properly disclosed.

"The congressman does not believe he was lobbied in Baku," said spokesperson Shaylyn Hynes. "He viewed the events as informational."

Hinojosa emphasized that "all expenses were also reported and approved. The purpose for the trip was to learn more about U.S. interests, and in my case, educational programs that the Azerbaijani government is developing."

Dominic Gabello, chief of staff for Rep. Michelle Lujan Grisham, D-N.M., said her boss used the trip as an "opportunity to learn more about the challenges Azerbaijan faces" and specifically questioned Azeri leaders about how they deal with poverty.

"She has not been lobbied about specific issues," Gabello said.

Vague tax records

Oksuz, a Houston public relations director, serves as president of the Turquoise Council. He told the lone U.S. journalist present in Baku that the event cost around $1.5 million and that he'd offered speakers fees of $2,500. Some accepted gifts of hand-woven rugs, too, he told the Washington Diplomat.

He leads two nonprofits that share the same suite in a Galleria office tower, tax records show.

Both groups were identified as sponsors or organizers of the Baku conference, and both have accepted money from SOCAR. One group, the Assembly of the Friends of Azerbaijan, operates as a U.S.-based public relations arm of SOCAR, according to foreign government lobbying disclosures filed in 2014.

Via email, Oksuz answered a few basic questions, but then repeatedly delayed and canceled interviews requested by the Chronicle. He did not respond to requests to provide updated financial records that his nonprofit must disclose under state and federal laws.

The Turquoise Council's 2012 nonprofit tax return, available on the Internet, is "bare bones," discloses no expenses related to trips for elected officials and provides unusually vague descriptions of major funding sources, said David Nelson, a Houston attorney who specializes in nonprofit law.

'Educational' trips

Records show the Turquoise Council shared Baku congressional trip expenses with four other interconnected and obscure nonprofit organizations run by Turkic Americans, all of which claim to use "educational" trips to promote cross-cultural understanding, according to a Houston Chronicle review of dozens of federal disclosure records and nonprofit tax returns.

The groups included the Turkic American Federation of Midwest, based in Chicago; an umbrella group called the Council of Turkic American Associations, based in New York City and the Turkic American Alliance, based in Washington, D.C.. Each group leader identified his own nonprofit as lone trip sponsor.

Faruk Taban, leader of the Turkic American Alliance, said his group works to coordinate efforts among 240 different community associations. Generally, those groups work to "foster dialogue and understanding between Turkic states - in this specific case, Azerbaijan - and the U.S. Our work focuses as much on promoting understanding between the countries as between the communities," he said via email.

Many of those nonprofits are led by followers of Fetullah Gulen, a moderate Turkish ex-imam who lives in exile in an enclave in Pennsylvania but wields a philosophical and political influence throughout the Islamic world. Many Gulenists are involved in prep schools in Turkey and in Azerbaijan, as well as in charter schools in the United States, including the Harmony Schools in Texas.

Denies hiring lobbyists

Collectively, Turkic groups have funded 272 foreign trips for members of Congress and their staffs from 2009-2013, according to information analyzed by the Chronicle from a database of travel data compiled by LegiStorm. Together they have helped make Turkey the top foreign travel destination for members of Congress, after Israel. Trips to Azerbaijan are far less common.

Oksuz said the Turquoise Council has no formal ties to Gulen. He denied retaining any lobbyists or foreign agents in disclosures he made as a Baku 2013 trip sponsor.

Other records show that a SOCAR official in Azerbaijan, who normally would have nothing to do with visa approvals, helped Oksuz obtain visas for 21 people, including members of Congress and a lobbyist, Ari Mittleman of the Washington firm Roberti&White, a registered foreign agent.

Records show lobbyists attended the conference - and two reported meeting with congressmen the day of their 12-hour return flight to the US. There is no rule against lobbyists and congressmen meeting on foreign soil, though there is one forbidding them from accompanying each other on trips.

"Once they get members overseas, it's kind of back to the wild, wild West of lobbying," said Freeman. "So long as the foreign agent and policymaker are overseas; the requirements for reporting meetings are void."

Historical connection

Azeri interests have continued conversations with D.C. lawmakers with help from one of the nonprofits run by Oksuz. In April, the Assembly of the Friends of Azerbaijan held another "U.S.-Azerbaijan: Vision for Future" convention, this time at the Willard Hotel in Washington. It is the lobby of the Willard, where influential men once stood around hoping to buttonhole President Ulysses S. Grant, that inspired the term "lobbyists."

Many of the same sponsors from last year returned, including SOCAR, BP and ConocoPhillips. But several U.S. lawmakers advertised as speakers did not show up. Then came a late announcement: Rep. Steve Stockman would speak. Stockman walked to the podium and, in a booming voice, called for the U.S. to "stand by" Azerbaijan.

"We have a lot of friends in the media who want to criticize this country, but I've been there," he said. "The future is there … One day I hope for a direct flight from Houston to Baku."