The former president of a Houston nonprofit pleaded guilty Monday to charges of concealing that a 2013 congressional delegation trip to Azerbaijan was funded by that country’s government.

The Justice Department indicted Kemal Oksuz, aka Kevin Oksuz, 49, in September, alleging that he lied on disclosure forms filed with the House Ethics Committee prior to and following a privately sponsored congressional trip to Azerbaijan. Oksuz was extradited from Armenia.

He pleaded guilty to one count of “devising a scheme to falsify, conceal and cover up material facts from the U.S. House of Representatives Committee on Ethics,” according to the Justice Department. Oksuz will be sentenced on Feb. 11 before U.S. District Court Judge Tanya S. Chutkan for the District of Columbia.

Oksuz admitted that he falsely reported on official disclosure forms that his nonprofit, the Turquoise Council of Americans and Eurasians, had not accepted outside funding for the congressional trip. He used the nonprofit to funnel money to fund the trip from the State Oil Company of Azerbaijan Republic, which is an oil and gas company wholly owned by the government of Azerbaijan.

“No House Member or employee may accept the payment of travel expenses … from a private source to participate in a trip … without prior written authorization from the [Ethics] Committee pursuant to these regulations,” according to the Ethics rules on travel.

The House Ethics Committee in 2015 determined that there was “no evidence” that 10 lawmakers and more than 30 aides “knowingly violated” congressional rules during a 2013 trip. Privately sponsored travel by House members and staff is regulated by the House Ethics panel. The Ethics Committee made the members and staff return the gifts they received, which included rugs and crystal tea sets.

Nonprofit groups are allowed to sponsor “educational” trips for lawmakers and staff, but the Ethics Committee must review the itinerary, which they did for the May 2013 trip. Nonprofit groups must also certify that they are the source of the funding for the trip. That is where Oksuz went outside the law.