In certain cases, the right to correspondence can be limited. Authorities may open and read, censor, or in extreme cases withhold detainee correspondence. Any interference with correspondence must be justified on grounds clearly set out in law or prison regulations, and any restriction must be done to achieve a legitimate purpose. This could include protecting the safety and security of the prison, preventing re-traumatization of a victim or interfering with an investigation or trial.
If opening mail is considered necessary for the safety and security of the prison in most cases random sampling should be sufficient to address these concerns, rather than opening all mail. As a safeguard, a supervisor or manager should have specific responsibility for opening and reviewing mail, and be bound by obligations of confidentiality. Where it is deemed necessary to read and censor or withhold particular prisoner’s correspondence this should be ordered by an independent authority such as a magistrate (see further, section on ‘pre-trial detainees’ below).
Both incoming correspondence from and outgoing correspondence to a protected person such as a detainee’s lawyer should be confidential. If authorities have reason to believe that contraband is contained within a letter from a protected person, or that the letter is not in fact from who it says it is from, the letter may be opened but this should be done in the presence of the detainee and the contents should not be read. The fact that protected mail is opened by authorities should be recorded in a register.