What is the ruling on a married man marrying another woman through an unregistered marriage in a country that prohibits polygamy and the official registration of such a marriage, especially if her guardian does not approve except in secret?

It is not permissible to marry a woman without a wali (guardian). The presence of a father prevents the brother from marrying off his sister. It is permissible for the father to refuse to marry off his daughter if there is no recognized document, due to the corrupting consequences that may arise from such a marriage. Documenting marriage contracts is among the Masalih Mursalah (undisclosed public interests) that are consistent with Sharia, as it preserves the rights of both the wife and the husband, establishes the lineage of children, and prevents a man from marrying more than four women. A woman's father being prevented from marrying her off due to the state's disapproval of polygamy is religiously acceptable, and it is not permissible to marry her without her father's permission.

Urfi marriage (customary marriage) has two forms: The first is marrying secretly without the wali's consent, which is invalid. The second is marrying with the wali's consent but without public announcement or documentation, which is valid in terms of its pillars but entails many corrupting consequences. In the case mentioned, the prevention came from two sides: the wali's disapproval and the lack of documentation.