"I was told to provide the names, addresses and activities of any Venezuelan or Cuban doctors or field workers I come across during my time here," Fulbright scholar John Alexander van Schaick told ABCNews.com in an interview.
His account matched that of Peace Corps members and staff who claimed the embassy official in Bolivia instructed an entire group of volunteers to report on Cuban and Venezuelan nationals.
The State Department said any such request was "in error" and violated a U.S. policy prohibiting using Peace Corps personnel or Fulbright scholars for intelligence-gathering.
"We take this very seriously and want to stress this is not in any way our policy," a senior State Department official told ABCNews.com.
Van Schaick told ABC the request came during a mandatory orientation with Assistant Regional Security Officer Vincent Cooper.
"He said, 'We know the Venezuelans and Cubans are here, and we want to keep tabs on them,'" said van Schaick.
"These are serious incidents that we will investigate thoroughly," Bolivia's Foreign Minister David Choquehuanca told ABC.