Malih, who planned to travel on Wednesday from Damascus to the United Arab Emirates for a private visit, was prevented by authorities from boarding his flight, his Human Rights Association in Syria said in a statement.
"The travel ban is linked to the fact that Malih made a speech two months ago to the German parliament that addressed the human rights situation under the state of emergency," in place since 1963, his association said.
Malih travelled to Germany in December to participate in hearings before the Bundestag's human rights committee.
One month ahead of the 41st anniversary of the Baath party's rise to power in Syria, more than 1500 democracy activists, lawyers and intellectuals have signed a petition demanding radical changes from President Bashar al-Asad.
The petition - published on Tuesday in the Lebanese newspaper al-Nahar, which regularly features contributions from Syrian opposition figures - called for political reforms, the lifting of the state of emergency and the release of all political prisoners.
The intellectuals say the state of emergency - imposed when the Baath party assumed power - has "led to the paralysis of society and to the imprisonment of thousands of citizens for political reasons."
It also demands the government shuts down special state courts where defendants have no right of appeal and that arbitrary arrests be halted.