Images in the Indian Express showed dozens of men sitting cross-legged in a field clad only in underpants, with many resting their test papers on their thighs, while a uniformed supervisor stood guard.
The paper quoted an army source as saying they took the radical step to “save time on frisking so many people” after more than 1,000 candidates turned up.
“We had no option but to comply with the instructions even though it felt odd,” one told the paper.
An army spokesman in New Delhi refused to comment on the report, which came a year after police in Bihar said they had arrested around 1,000 aspiring officers for paying people to sit their exams for them.
Using methods ranging from old-fashioned crib sheets to high-tech spy cameras, cheating is common in India, mostly to secure good school grades and highly-sought government jobs.
The impoverished state of Bihar, also one of the most populous, is especially notorious for cheating.
Last year a scandal in the state that saw relatives scale the walls of a school exam centre to pass notes to candidates went viral and made national headlines.