A family friend says the 16-year-old son of a Chinese couple targeted by authorities in a crackdown on rights defense lawyers has been barred from traveling to Australia to attend high school and placed under police surveillance.

Chen Jiangang said Saturday that Bao Mengmeng had been told not to inquire about the whereabouts of his parents, who are believed to be detained by authorities amid Beijing's massive crackdown on the lawyers.

Bao's mother, Wang Yu, is a prominent rights defense lawyer who disappeared on July 9, hours after she dropped her son and husband off at an airport.

The teenager was released two days later, but the father is still missing.

Calls to police in the northern city of Tianjin, where Bao is under surveillance, were not answered on Saturday.