From Sahih Bukhari (Hadith 88):
Narrated `Abdullah bin Abi Mulaika:`Uqba bin Al-Harith said that he had married the daughter of Abi Ihab bin `Aziz. Later on a woman came to him and said, "I have suckled (nursed) `Uqba and the woman whom he married (his wife) at my breast." `Uqba said to her, "Neither I knew that you have suckled (nursed) me nor did you tell me." Then he rode over to see Allah's Messenger (ﷺ) at Medina, and asked him about it. Allah's Messenger (ﷺ) said, "How can you keep her as a wife when it has been said (that she is your foster-sister)?" Then `Uqba divorced her, and she married another man
Reference: Bukhari 88