The Australian government has expressed "alarm" at China's crackdown against Muslim minorities and called for an end to the detention of up to 1 million people in indoctrination camps.

In the strongest Australian intervention yet on the Chinese government campaign, officials delivered a statement at the United Nations highlighting reports that minority groups and human rights advocates have been tortured or otherwise targeted by authorities.

Security personnel in Xinjiang. Credit:AP

"Australia shares the UN [Committee on the Elimination of Racial Discrimination's] alarm at numerous reports of detention of large numbers of ethnic Uighurs and other Muslim groups held incommunicado and often for long periods without being charged or tried, which exacerbates rather than prevents religious extremism," the statement said.

"Australia recommends that China cease the practice of arbitrarily detaining Uighurs and other Muslim groups in Xinjiang ... [and] immediately release individuals currently detained."