The Central Commission for Discipline Inspection said in a note on its website that Zhao Xinwei was guilty of serious violations of discipline, which usually means corruption.
Unusually, however, it also accused Zhao of failing to toe the party line on the fight against separatism, terrorism, religion, extremism, and other sensitive issues.
Zhao “openly made statements opposing central government and autonomous region work instructions on major issues”, the commission said.
No details were given and it was not clear whether Zhao was accused of being too hardline or not harsh enough.
While Beijing warns consistently about the threat of separatist violence by radicals from among Xinjiang’s native Muslim Uighur ethnic group, it is also wary of further alienating the general Uighur population with offensive or condemnatory language.
Zhao had already been formally arrested. He has now been kicked out of the party and fired from his job.
Xinjiang has been under heavy security since deadly riots in 2009 that pitted Uighurs against ethnic Chinese migrants.
Those measures were tightened further following a wave of attacks in Xinjiang and other parts of China blamed on Uighur separatists adhering to a radical form of Islam.