The photo is reported to have been taken a few days ago, in the eastern Syrian city of Raqqa, considered to be the unofficial capital of the Islamic State extremist group Isis.
Mahmoud served four years in an Austrian prison for joining and actively supporting al-Qaeda and its affiliates. He is now linked to Isis and calls himself Abu Usama al-Gharib.
He is reported to have married Ahlam Al-Nasr, an Isis propaganda official known as the “poet of the Islamic State” a few weeks ago.
Earlier this year an extradition request from Austria for Mahmoud was rejected by the Turkish authorities. According to the Kurier newspaper there was some speculation that he was released from a detention camp for foreign nationals in exchange for Turkish hostages.
In Austria Mahmoud was considered a troublesome hate preacher but an advisor to the German secret service has painted a different picture, saying that he is an important ally of the Islamic State and may even be one of its founders.
"Mohammed Mahmoud is an enormously important figure. One should not be fooled by his somewhat ridiculous appearances on the Internet,” German jihadism expert Guido Steinberg recently said to the press. Steinberg added that it was “completely irresponsible” for Turkey to free him.
Peter Neumann, Director of the London based International Centre for the Study of Radicalisation, has said that Mahmoud caused a “chain reaction” by founding the first militant salafist movement in Central Europe (Millatu Ibrahim) and radicalising Austrians and Germans.
Mahmoud, originally from Egypt, was arrested in Austria in 2007 after authorities said they became alarmed when he started to buy components for a possible suicide belt and his organisation Media Front published a video threatening to carry out attacks in Germany and Austria if they did not withdraw their troops from Afghanistan.