Tohti, an ethnic Uighur and Muslim who has been critical of China's policies toward minorities, was shackled and denied food in prison following a March train station bombing in the western city of Kunming, his lawyer Li Fangping said. The bombing killed 29 people and was blamed on Muslim Uighur separatists.
Although Tohti has been jailed for months, he met with Li for the first time this week.
Tohti, detained since January, has been charged with the crime of separatism. Despite his critical writing, there is no record of Tohti favoring the cause of Uighur separatism, and he maintains his innocence.
Li said Tohti went on a hunger strike in prison to protest food he was served that violated Islamic dietary law, and was force-fed by authorities.
China has reacted harshly to violent attacks in western China by suspected Uighurs separatists. A crackdown, ordered by Chinese president Xi Jinping, has resulted in numerous arrests and convictions. Thirteen people were convicted on terrorism-related charges and executed, earlier in June, and several mass-sentencings were conducted, publicly in sports stadiums, before large crowds.