Documents, allegedly from the CIA, have leaked out regarding the search for Dr Leonid Pavel. Pavel seems to have been working as a nuclear physicist and first came to the attention of the intelligence community when he presented a controversial theory at an IEEE Symposium three years ago. However, Dr Pavel has disappeared and a militia claiming to be protecting him has contacted US authorities seeking a payment to ensure his continued protection until finally handing him to US authorities. Following initial contact there has been no further known communication between US authorities and Dr Pavel's protector's.
Details regarding the group is unknown, nor is there solid evidence that they indeed have the doctor. Given Pavel's knowledge of nuclear fuel cycle technology and reactor designs confirming his current condition, location and ultimate extraction has been deemed a high priority task of the intelligence services.
Part of Pavel's dossier: Source
Part of transcript with Pavel's "protection": Source
Without a doubt Pavel's knowledge and expertise would be of use to any number of governments and non-state actors, locating the doctor will be in all our interests.