The wife of a prominent Uighur scholar says he has been formally arrested and accused of secession more than a month after being taken away by force from their Beijing home without explanation.

Guzaili Nu'er said she received the arrest warrant on Tuesday and learned that her husband, Ilham Tohti, is being held in a detention center in the far-western region of Xinjiang.

Ilham Tohti is an economics professor at Beijing's Minzu University and has been outspoken about the rights of China's Turkic Uighur ethnic minority in Xinjiang.

Authorities have accused him of spreading separatist ideas, inciting ethnic hatred and engaging in separatist activities.

His lawyer, Li Fangping, says the secession charge is groundless.