Is a confession made under duress valid?

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A confession made under coercion (ikrah) is invalid. If a man is beaten to confess to adultery (zina), the prescribed punishment (hadd) is not incumbent upon him, and the adultery is not established against him. Scholars are unanimous on this point: a coerced confession does not necessitate the imposition of a prescribed penalty. The evidence for this is found in the statement attributed to Umar, may Allah be pleased with him, that a man is not trustworthy regarding himself when he is starved, beaten, or restrained. Furthermore, a confession is established only when there is a prompting toward truthfulness and an absence of suspicion. Since a rational person is not suspected of intending self-harm, when coercion is present, it is highly likely that the confession was made solely to repel the harm of the coercion, thus negating the presumption of truthfulness, and the confession is rejected.