According to a confidential ethics report obtained by The Washington Post, SOCAR (the state-owned oil company of Azerbaijan) funded an all-expenses paid trip to Baku in 2013 for ten members of the U.S. Congress and 32 staff member to a conference in Baku.

The 70 page report by the Office of Congressional Ethics claims that SOCAR allegedly funneled $750,000 through nonprofit corporations in the U.S. to conceal the source of the funding.

The conference, titled “U.S.- Azerbaijan Convention: Vision for the Future,” took place on May 28 and 29, 2013.

During the previous year, SOCAR and several large energy companies sought exemptions for a $28 billion natural gas pipeline project in the Caspian Sea from U.S. economic sanctions being imposed on Iran.

The congressional investigators weren’t able to conclude whether lawmakers used their official positions to benefit SOCAR or the pipeline project. They also found no evidence that the lawmakers or their staff members knew that the conference was being funded by a foreign government.

SOCAR has released a statement claiming that its support of the conference was no secret and blaming the nonprofits for not filing the proper disclosures.