Hamburg - Iranian secret police are operating on German soil, monitoring and even filming exiled Iranian dissidents, according to a counter-subversion agency in Hamburg Thursday.

ARD public television said it would broadcast a documentary Thursday evening on the issue.

"We know that the Iranian services send their own people to mingle in when there are demonstrations (against Teheran)," said Manfred Murck, deputy chief of the Hamburg state Agency for the Protection of the Constitution, in the documentary.

"We have evidence that they video these events so that they can identify the people afterwards," he added. ARD released details of the interview to other media.

The agency is charged with stopping subversion and foreign espionage in Germany.  (dpa)