The director of the immigration detention center, etc. is to permit detainees to send and receive letters to and from other persons, except where they are withheld pursuant to the provisions of Article 55-61.
Read this with the articles around it
detaineemachine translation
「被収容者」
A person held in an immigration detention center or other immigration detention facility.
Defined inArticle 55-4, paragraph (1)· applies only in this chapter and in Article 71-6
director of an immigration detention center, etc.machine translation
「入国者収容所長等」
The director of an immigration detention center or the director of a regional immigration services bureau.
Short name set inArticle 55-5, paragraph (1)· applies only in this chapter and in Chapter 8