Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) narrated from Sayyiduna Umar (may Allah be pleased with him) that he gave a false witness eleven lashes, then said: "Do not imprison people on the strength of false witnesses, for we accept from witnesses only those who are upright."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20492