An investigation by the Department of Defense has cleared two Massachusetts Institute of Technology missile-defense researchers who were accused of fraud.

According to an article in The Boston Globe, the investigation concludes that the two researchers omitted some information that should have been included in their 1998 study of software for the missile-defense system, but that they had plausible explanations for leaving the material out. The two researchers work for MIT’s Lincoln Laboratory.

The research findings were called into question by a whistle-blower who worked for a contractor involved in the missile project and by Theodore A. Postol, an MIT professor of science, technology, and national-security policy who has been a longtime critic of missile-defense technology. MIT’s efforts to conduct its own investigation into the fraud allegations were hampered by the Defense Department’s refusal to release some classified information related to the study (The Chronicle, March 6, 2006). —Lawrence Biemiller