The Government deals harshly with all opponents, including those engaging in religious practices deemed unacceptable to the regime. Religious and human rights groups outside of the country have provided numerous, usually unconfirmed, reports that members of underground churches have been beaten, arrested, tortured, or killed because of their religious beliefs. Defectors interviewed by a former humanitarian aid worker claimed that Christians were imprisoned and tortured for reading the Bible and talking about God, and that some Christians were subjected to biological warfare experiments. The Government effectively bars outside observers from confirming these reports. However, the collective weight of anecdotal evidence over the years of harsh treatment of unauthorized religious activity lends credence to such reports.

In 2002, witnesses testified before the U.S. Congress on the treatment of persons held in prison camps through the early 1990s. The witnesses stated that prisoners held on the basis of their religious beliefs generally were treated worse than other inmates. One witness, a former prison guard, testified that because the authorities taught "all religions are opium," those believing in God were regarded as insane. He recounted an instance in which a woman was kicked repeatedly and left with her injuries unattended for days because a guard overheard her praying for a child who was being beaten. Another individual testified that in 1990, while serving a sentence in a prison that had a cast-iron factory, she witnessed the killing of several elderly Christians by security officers who poured molten iron on them after they refused to renounce their religion and accept the state ideology of juche.