What is the ruling when an heir confesses to the existence of an inheritor who would otherwise exclude them from inheritance?

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If an heir admits to the existence of a non-inheritor (a person whose existence would invalidate their own inheritance share), their inheritance share is forfeited. For example, if a sister from the father's side admits to a full brother, her share is voided. In a case involving a husband and a full sister, if the sister admits to a full brother, her share falls away. The estate is divided between the husband and the sister by halves, provided they believe her in the first scenario. In the second scenario (where the sister admits a full brother), the husband receives half, and the remainder is divided between the brother and the sister into three parts. If the heirs deny the confession, the admitted person receives one-seventh of the estate, following the three established opinions regarding the first scenario, and this amount is given to the parents in the second scenario.