A German official on Thursday said that the recent clampdown on Chinese dissidents was a "burden" on relations between the two countries, DPA reported.
Markus Loening, commissioner for human rights with the German Foreign Office, was speaking to journalists at the end of a five-day visit to Beijing.
He criticized the "noticeably intensified" actions against activists in China, and said the arrest of dissident artist Ai Weiwei raised particular concerns about the rule of law.
The 53-year-old artist was held for six weeks without access to legal counsel or his family. Officials have said he is suspected of economic crimes, although no details of any charges have been released.
His wife was granted a first brief visit at the weekend. Lu Qing said her husband reported that his health was "OK," and that he had been allowed to take medication for his diabetes and high blood pressure.
The German envoy told reporters that during his meetings with Chinese officials, he "said that the sum of the incidents was simply difficult, and a burden from the German point of view."
He also mentioned the incarceration of Nobel Peace Prize laureate Liu Xiaobo, and widespread house arrests imposed on human rights activists.