What is the ruling of the religion regarding the marriage of a woman whose husband died and then returned after she had married his brother? Is the second marriage null and void?

If the wife receives news of her absent husband's death, observes the 'iddah (waiting period), and then remarries, and then her first husband reappears:

- If this occurs before the second husband has consummated the marriage with her, she is returned to the first. - If the second husband has consummated the marriage with her, the well-known opinion is that she is not lost to the first husband and is returned to him, even if she has borne children from the second. - Some scholars have stated that the first husband is given the choice between taking his wife back or leaving her with the second husband, and he is entitled to the dowry he gave. - The matter must be referred to a Shar'i court to examine the details of the issue and rule upon it.