Beijing has attracted more criticism over its arrest of prominent Chinese dissident Hu Jia.
Brussels has said it plans to lodge a formal protest “very soon”.
Washington and rights groups condemned the activist’s arrest last month on charges of inciting to subvert the government.
Police in China have also prevented Hu’s wife, their new baby and her aged mother from leaving the couple’s Beijing home.
Asia analyst Willem van der Geest:
“It’s setting an example. The Chinese always have the approach in corruption cases (that) they hit somebody big. In this case they hit somebody prominent with contacts abroad. But it’s not more than that. It will be a temporary phase, largely inspired by the Olympics, coming up in August.”
Hu first came to prominence over his advocacy for AIDS sufferers in rural China.
A Chinese Foreign Ministry spokeswoman reiterated warnings against attempts to “politicise” the Olympic Games by tying it in with human rights issues.