In April 2015, a sworn statement submitted in a Nevada lawsuit between rival casino moguls Steve Wynn and Japan's Kazuo Okada contained an unusual assertion. Its author said Wynn's head of security had asked to meet him in Japan and then persuaded him to travel to the United States to talk to federal agents pursuing a different matter: a criminal bribery probe into Okada.

The person who provided the statement, Yoshitaka Fujihara, then an executive at Okada's Universal Entertainment Corp., said he did not pay for his business-class flights, lodging and meals for two meetings with the FBI in California. Wynn Resorts has since acknowledged covering those costs and making other arrangements for Fujihara, as well as other potential witnesses, to meet with the Feds.

Fujihara's account helped prompt the judge in the Nevada case to allow questioning into Wynn Resorts' role in facilitating the separate criminal investigation into Okada. As a result, the case has opened a rare window into the workings of a U.S. overseas bribery probe and the role played by a company in the investigation of a rival, according to a Reuters review of court documents and interviews with people involved.