Musannaf Ibn Abi Shayba 19:818

Abu Bakr narrated to us, he said: Jarir narrated to us, from Mughira, from Hammad, regarding a man who is absent from his wife and has not consummated the marriage with her, and she comes with a pregnancy or a child. He said: If his absence was in a distant land, she is not to be believed, and the prescribed punishment (hadd) is to be established upon her. And if he was in a nearby land where they see that he could come to her secretly, she is to be believed regarding the child, that it is from her husband.