The Pentagon announced the investigation Jan. 15, saying 34 nuclear weapons officers allegedly either cheated on their monthly proficiency test or knew about the cheating and kept quiet.
A military official, speaking on condition of anonymity, told NBC News that number has nearly double though the official wouldn't give a precise number of people being investigated.
The official would not comment on whether those under investigation had been suspended though "it is safe to assume that if they are under investigation, they are not pulling duty," the official said.
Air Force Chief of Staff Gen. Mark Welsh said the officers allegedly shared exam answers during the August and September 2013 tests by cellphone.
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