The United States is investigating a potential conspiracy after at least 10 scientists connected to US nuclear secrets and rocket technology went missing or died under suspicious circumstances over the past few years.

Republican members of the House Committee on Oversight and Government Reform cited tabloid reports from The Daily Mail and The New York Post as the impetus for their inquiry. Reps. James Comer (R-Ky.) and Eric Burlison (R-Mo.) sent letters to the Department of Energy, Department of Defense, Federal Bureau of Investigation (FBI), and National Aeronautics and Space Administration (NASA).

In the letters, the lawmakers stated that the reports had raised "questions about a possible sinister connection between a string of mysterious deaths and disappearances."

"If the reports are accurate, these deaths and disappearances may represent a grave threat to US national security and to US personnel with access to scientific secrets," the letters said.