The espionage investigation of the Maryland scientist charged with attempting to pass the nation’s most guarded secrets to Israel was triggered by a NASA inspector general probe into Stewart Nozette’s technology company, a source with knowledge of the investigation said.

Nozette was taken into custody Monday after he accepted $11,000 from an FBI agent posing as an Israeli intelligence officer in return for classified information on U.S. satellite systems and nuclear weaponry, according to federal authorities. Nozette, a former White House employee, worked on the U.S. government’s Star Wars missile shield program. The 52-year-old was held without bail in D.C.’s federal court Tuesday. His attorney declined to comment.