The German Foreign Office said Tuesday it was working "full out" to clarify if mistakes led to Mansour's arrest by police at Berlin's Tegel airport on Saturday, apparently on the request of Egypt, as he was about to board a flight to Qatar.
The star Arabic presenter of the Qatar-based TV news channel was released on Monday on the instructions of Berlin's state prosecutions office, amid widespread calls that he not be extradited to Egypt.
At a press conference in Berlin on Tuesday, Mansour described his release as a "clear message from Germany that it is committed to honoring and nurturing freedom of expression."
Mansour vowed to continue to "work for freedom."
And, he said he feared that the government of Egypt's President Abdel-Fattah el-Sissi had "succeeded in exporting some of its dictatorship, repression and violations to here in Germany."
Denied Egyptian charges
Over the weekend, Mansour publicly denied charges linked to his sentencing to 15 years jail in absentia by a Egyptian court.
The weekend events that culminated in Mansour's arrest and later release were sharply criticized on Tuesday by Renate Kunast of the German Greens party, who chairs the judicial committee of Germany's parliament, the Bundestag.
"'Something like this should never happen again," Kunast said.
"The arrest of Ahmed Mansour was a judicial and foreign policy embarrassment of the first order," she said.
Interpol turned down Egyptian request for international warrant
Berlin's "Tagesspiegel" newspaper on Tuesday said Mansour had not merely been in transit via Tegel on Saturday when arrested.
"It's also unclear why Mansour, if the arrest warrant had validity, was not arrested a week ago on arrival [in Germany]," the newspaper said.
News has also emerged that Interpol turned down an Egyptian request for an international warrant for Mansour last October, on the grounds that it amounted to political persecution.
On Monday, German ministries had faced questions about why the Egyptian extradition request was passed along in the first place to German federal police who monitor airports.
Egypt's military-led government has in the past accused Al-Jazeera of backing the Muslim Brotherhood, which it ousted from power in 2013.
Justice Ministry initiative?
Saad Djebbar, one of Mansour's lawyers, asked during an Al-Jazeera interview on Tuesday: "Where did the arrest come from? It came from the ministry of justice in Germany. That's what we concluded.
"But, it is mysterious, because, why arrest Mansour when you don't have any extradition treaty with Egypt?" Djebbar asked, referring to Berlin and Cairo.
"Secondly, the German judiciary [had] already ruled against repatriating any person to Egypt … or other countries … where people are ill-treated in detention centers or in prisons, or where the judiciary is not independent."
Olaf Boehnke, director of the Berlin office of the European Council on Foreign Relations, told the broadcaster that it was his "guess" that the Egyptian request had got "into the system."
"It sounded to me like a really big mistake," he said, given the recent visit to Berlin by Egyptian President Abdel-Fattah el-Sissi, which drew "a lot of criticism within Germany."
"That would have been a big scandal if they kept him here and sent him over to Egypt," he added.
Egypt 'pursuing' journalists abroad
Sherif Mansour, the Middle East coordinator for the Committee to Protect Journalists, told Al-Jazeera on Tuesday that Egypt was pursuing critical journalists internationally via lobbying.
"The Egyptian government is trying to abuse international law," he said. "The Egyptian government is already doing this."
In 2014, a television journalist was extradited to Egypt from Lebanon after a visit from Egypt's foreign minister to Beirut, he said.
"More recently, the Egyptian prime minister visited France and lobbied with the French government in order to shut down pro-Muslim Brotherhood stations."
"They have already silenced many of them inside [Egypt]," he said.
Egypt is still running a re-trial of several other Al-Jazeera journalists, on charges of alleged membership in a terrorist group and broadcasting falsified footage.
ipj/cmk (AFP, dpa, Reuters, AP)