Zhang Miao, detained in October amid a crackdown on mainland supporters of protests which shut down parts of Hong Kong, was held in Beijing days after returning from a reporting trip to the former British colony.
Read: Murder mystery: Journalist’s parents found killed
Her detention highlighted risks facing Chinese nationals who work for foreign media in China and are often subject to harassment from state security.
Zhang, who had worked for the Hamburg-based weekly Die Zeit, told AFP by telephone she was "safe" and on a public bus on her way home following her release.
But Zhang's brother and a family friend said state security on Friday morning detained her lawyer Zhou Shifeng.
"Three people took lawyer Zhou away, they covered his head," said the friend, who witnessed the detention at a hotel in the capital.
Angela Koeckritz, the former Beijing correspondent for Die Zeit, wrote in January that she had left China because of official pressure and repeated interrogations following Zhang's detention.
Read: International celebration: Journalists to mark Press Freedom Day
She said police held Zhang shortly after she attended a small-scale poetry reading in Beijing held in solidarity with Hong Kong pro-democracy activists.
Rights groups said at the time that dozens of people in the mainland were detained for expressing support for the demonstrations.
China tightly controls its domestic media, and bars locals from working as journalists for foreign outlets, though they are permitted to assist with reporting.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ