In 2010, Ian Brzezinski joined the Atlantic Council, a Washington think tank focused on foreign policy issues. The position, and a perch on Atlantic’s Strategic Advisory Group, seemed natural for someone with Brzezinski’s resume, which featured significant policy jobs at the Pentagon and on Capitol Hill.

When someone is getting paid, even innocuous statements look murky.

Of course, that kind of CV is a good fit for another type of Washington work, too. In March 2011, Brzezinski started up his own lobbying firm. That year, the Brzezinski Group reported two clients: Grupa LOTOS S.A., a Polish oil company, and Central Europe Energy Partners (CEEP), a nonprofit of which Grupa LOTOS is a member and founder. They paid him at least $101,000 to lobby the U.S. government on a Grupa LOTOS project to store petroleum in salt caverns in Poland. Since April 2012, Grupa LOTOS has paid Brzezinski an additional $24,000 a quarter--a total of $72,000--even though he hasn’t reported any direct lobbying contact with lawmakers.

The same month he started his lobbying firm, Brzezinski spoke at a conference in Poland co-sponsored by CEEP. On the agenda, he was listed as affiliated with the Atlantic Council. He discussed energy security and “the importance of salt caverns.” A summary on CEEP’s website reported that Brzezinski said the region should “follow the model of the USA and collect strategic [energy] reserves” and that salt caverns Grupa LOTOS wants to exploit were “perfectly suitable for storage of gas and oil.” And the following October, a month and a half after registering to lobby separately for Grupa LOTOS, Brzezinski spoke at a conference sponsored by the James A. Baker III Institute for Public Policy at Rice University. “Poland can play a significant role in reshaping Europe’s energy map,” said the agenda. “The United States, too, has a strong interest regarding the future of Poland’s energy industry.” Appearing on the same panel was the CEO of Grupa LOTOS. The title of his talk: "Project Caverns: Establishing a Strategic Petroleum Reserve for Poland."

Washington lobbyists are required by law to disclose who they work for, how much they get paid and what issues they advocate for. But they’re not obliged to mention it when they do other work—like, say, appear as a policy expert at a think-tank event. Brzezinski’s Atlantic Council bio, for instance, says he “leads the Brzezinski Group, which provides strategic insight and advice to government and commercial clients,” but it doesn’t disclose that he’s a registered lobbyist or identify his clients. The Rice University conference agenda listed Brzezinski as a senior fellow with the Atlantic Council without mentioning that he was lobbying for the company that wanted to build the project—or that another panelist was paying him. (Reached by phone, Brzezinski said he was unavailable and referred questions to the Atlantic Council; the Council did not return phone calls or emails requesting comment.)

Brzezinski’s role is hardly anomalous. We found at least 49 people who have simultaneously worked as lobbyists for outside entities while serving as top staff, directors or trustees of 20 of the 25 most influential think tanks in the United States, as ranked by the Think Tanks and Civil Societies Program at the University of Pennsylvania.