It is narrated from Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) led the prayer without ablution (wudu); the people's prayer was complete, but he (peace and blessings be upon him) repeated the prayer.
This is not strong, and what has preceded is sufficient.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4076