Hadith 1303Q2

عَنْ مَّالِكٍ أَنَّهُ بَلَغَهُ أَنَّ عُمَرَ بْنَ الْخَطَّابِ وَعُثْمَانَ بْنَ عَفَّانَ قَضَىٰ أَحَدُهُمَا فِي امْرَأَةٍ غَرَّتْ رَجُلًا بِنَفْسِهَا وَذَكَرَتْ أَنَّهَا هُرَّةٌ، فَوَلَدَتْ لَهُ أَوْلَادًا فَقَضَىٰ أَنْ يُّفْدِيَ وَلَدَهُ بِمِثْلِهِمْ.
Sayyiduna Umar ibn Khattab (may Allah be pleased with him) or Sayyiduna Uthman ibn Affan (may Allah be pleased with him) gave the ruling: If a woman deceives someone by saying, "I am free," then marries and has children, and afterwards it is discovered that she is someone’s slave-girl, then by giving a slave-boy or slave-girl like her children, he can ransom his children.

Imam Malik (may Allah have mercy on him) said that in my view, giving the price is better.
Hadith Reference موطا امام مالك رواية يحييٰ / كتاب المدبر / 1303Q2
Hadith Takhrij «فواد عبدالباقي نمبر: 40 - كِتَابُ الْمُدَبَّرِ-ح: 6ق1»