Nafi' narrates from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that a man performed li'an against his wife in the time of the Prophet (peace and blessings be upon him), and the Messenger of Allah (peace and blessings be upon him) separated the two of them and gave the child to the mother? He said: Yes.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللعان / 15353