What is the ruling of Islamic law on a wife who married without the presence of family witnesses, then separated from her husband who refuses to divorce her and has married another woman, while she is unable to marry because she is still legally his wife, and there is no judge to grant her a divorce?

If a marriage takes place without the permission and knowledge of the guardian (wali), the preponderant opinion is that it is invalid, despite a difference of opinion among scholars regarding the validity of such a marriage contract (nikah). If a couple separates in a marriage whose validity is disputed, then a divorce is necessary. Sheikh Ibn Uthaymeen clarifies that divorce occurs in a disputed marriage if the one initiating the divorce believes in the validity of the marriage. If he does not believe in its validity, there is a difference of opinion among scholars, but the preferred view is that divorce takes place so that the woman is not prevented from marrying someone else.

Therefore, if the couple believes in the validity of the aforementioned marriage, then a divorce is necessary to formalize the separation. If the husband refuses to divorce or grant a khul' (a woman-initiated divorce), and the wife is harmed, she should refer her case to a Muslim judge, or to scholars in Islamic centers in non-Muslim countries.