Hisham bin Urwah narrated from his father that they brought their dispute before Sayyiduna Uthman (may Allah be pleased with him), and Sayyiduna Uthman (may Allah be pleased with him) gave the judgement in favour of Sayyiduna al-Zubayr (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الولاء / 21519