What is the ruling when the husband denies naming the dowry (Sadaq) and claims the marriage was without any dowry, after consummation?

Primary text

If the wife claims a dowry equal to or less than the customary dowry (Mahr al-Mithl), the amount claimed is obligatory upon the husband without requiring an oath from him. This is because if the husband were to admit her claim (even if it were Mahr al-Mithl), Mahr al-Mithl would be due, rendering the dispute meaningless. If the wife claims an amount less than Mahr al-Mithl, this implies she admits to accepting less than what is due, thus her statement is accepted without an oath. However, if she claims an amount exceeding Mahr al-Mithl, the husband must take an oath to negate her claim, and in any case, Mahr al-Mithl is obligatory upon him.