The FBI declined further comment on Tuesday. A Justice Department spokesman in Honolulu did not return a call seeking comment.
Bishop was married until last year, according to state documents in Utah. His ex-wife declined comment when approached by The Associated Press on Tuesday at her home in Odgen, Utah.
Her neighbor, Sandra Doyle, said it was clear Bishop was having an affair with a Chinese woman prior to the divorce. Doyle, who said she is friends with the ex-wife, said the girlfriend was a university student in the District of Columbia, though she didn't know which school.
Doyle said neighbors knew Bishop worked for the government in Hawaii but were unclear on his exact job.
Larry Wortzel, a member of the U.S.-China Economic and Security Review Commission, said China has used sexual entrapment as a means to gather intelligence before and the allegations aren't surprising.
As an Army reserve officer and defense contractor, Bishop would have received security briefings on this and understood "how sex may be used for intelligence targeting," Wortzel said.
Whether U.S. national security was damaged by any of the alleged disclosures would depend on how detailed the information was and whether the woman knew any of it was classified, said Carl Baker, director of programs at Pacific Forum Center for Strategic and International Studies.
Information on weapons could be harmful because it could tell a potential enemy what U.S. weapons system can do as well as what capabilities the adversary would need to develop to counter U.S. capabilities, he said.
Bishop's position wouldn't have given him access to specifics about weapons technology, though, Baker said.
Leaked details on military plans might also be detrimental.
"That's an important part, because if you divulge enough information about the planning process, you end up giving information that reveals a strategy and how you could counter that strategy," Baker said.
The key issues for any trial will be Bishop's intent and the sophistication of the information he passed on, Baker said.
Bishop is charged with one count of communicating national defense information to a person not entitled to receive it and one count of unlawfully retaining national defense documents and plans.
Associated Press writers Eileen Sullivan, Lolita Baldor and news researcher Monika Mathur in Washington, D.C., Annie Knox in Ogden, Utah and Oskar Garcia in Kapolei, Hawaii, contributed to this report.