A man who had been fitted with an electronic ankle tag as a surveillance measure was allowed to leave Germany unhindered on a commercial flight, according to press reports.

Police said 35-year-old Hussein Z., a refugee from Syria, boarded a flight to Athens from Hamburg on October 11, a few days after telling police that he wanted to get his sick son from a hospital on the Turkey-Syria border. According to Der Spiegel, he also contacted Hamburg police after his arrival in Turkey.

Hussein's ankle tag was being tracked by the German police's central tracking agency, GÜL, in Bad Vilbel, Hesse. Officers reported him missing when his signal disappeared from their system — and then reappeared 2,800 kilometers (1,700 miles) away in Athens. It remains unclear whether GÜL was informed by the Bavarian police, who were overseeing his detention, of his plans to leave the country.

According to a statement by Bavarian police, the man had come to their attention during his stay in the town of Aschaffenburg because of "aggressive behavior and attacks" on others in the shelter where he was living, as well as after making "various threats."

'A concrete danger'?

Police said the man was given a "long-term custodial sentence," from which he was released on October 4. "As a result of the ensuing surveillance measures, the Syrian refugee showed clear signs of psychological stabilization, which were confirmed when he asked to join his family, his mother and sister, in Hamburg." He then traveled to Athens on October 11. Police said authorities in Greece and Turkey were informed of his plans.

There is no law that prohibits people from boarding planes while wearing an electronic ankle tag. And a spokesman for the Bavarian police confirmed to DW that there was no legal reason to prevent the man's departure. As he explained, there was no evidence that the man was planning any kind of crime. The spokesman said ankle tags could be fitted without indication of "a concrete danger."

According to Der Spiegel magazine, however, Germany's federal prosecutor opened an investigation into Hussein in June after witnesses testified that he had had contact with rebels in Syria and was seen fighting in a video uncovered by the Bavarian police. But the investigation was dropped for lack of evidence. Bavarian police would not confirm any of this information. The spokesman said it was "correct" to describe him as a "potential threat with an Islamist background."

A spokesman for Bavaria's state Interior Ministry said Hussein's refugee status had been "temporarily revoked." He has been barred from re-entry into Germany and the Schengen Area.

The tags are tracked at a central point in Bad Vilbel

Why ankle tags?

The use of electronic ankle tags in Germany is generally restricted to tracking sex offenders and people released from jail on probation. The tags are supposed to set off an alarm when the wearers enter specific areas. Their use for what German intelligence agencies call "Gefährder" — people who could potentially carry out terrorist attacks — was made possible in new security measures introduced by the government in the wake of the truck attack on a Christmas market in Berlin last December.



Very few police forces in Germany have made use of the tool, and many officers believe that ankle bracelets are ineffective for keeping tabs on potential terrorists. "It's very difficult to define the area where they're not allowed to go, which is the point of ankle tags," Oliver Malchow, chairman of the GdP police union, told DW in October. "This is a very big intervention just to find out where someone is — an ankle tag is no help in finding out what they're doing there or who they're meeting."

On Friday, Malchow said he felt "somewhat vindicated" by the reports about Hussein Z. "The fact that these people can still travel all around Germany even though not all the states have brought in the law governing ankle tags shows how ineffective they are," he said. "The ankle tag as an instrument for preventing danger can only work if it there is a single rule across Germany."

Editor's note: Deutsche Welle follows the German press code, which stresses the importance of protecting the privacy of suspected criminals or victims and obliges us to refrain from revealing full names in such cases.