Ibn Abi al-Uja
Abdul Karim Ibn Nuwayreh, an atheist and dualist in the 8th century. It is said that he was th efollower of Manes (Persian famous painter who claimed to be a prophet). Abi al-Uja was against Islam religion. He was the student of Hasan Basri (famous preacher of Basra 642 – 728) but then separated fro monotheism and tried to ruin Muslims’ beliefs. Hw counterfeited Hadiths and circulated them among people, he was going to change and alter Islamic religious law. He had a discussion with Mufazzal Ibn Umar Ja’fi, on denying the existence of God, Mufazzal #### answered him harshly. Then travelled to Mecca and visited Imam Sadeq (the 6th Imam of Shias) “p.b.u.h”. The Imam accused him of not believing in God and the Prophet. But Imam Sadeq answered him fully. Although he knew himself as a perfect person and had some disciples and followers, but the scholars did not believe him. Ibn Abi al-Uja was accused of atheism and hanged by order of the governor of Kufa – Iraq in 772. At the time of his death, confessed that he had counterfeited 4000 Hadiths.
Sources :
Islamic encyclopedia -vol. 2