Hussein Abdel Ghani was arrested on Wednesday in the Red Sea resort of Dahab and accused of broadcasting false information liable to harm Egypt's reputation, the TV station said.
The interior ministry claimed Mr Abdel Ghani had falsely reported a blast in eastern Sharkia province.
A spokesman said: "[Hussein Abdel Ghani] said there were incidents in Sharkia and nothing happened. He's spreading confusion.
"When he said there was an explosion in Sharkia, leading everyone to ask about it, about something that didn't happen, where did he get that from?"
Mr Abdel Ghani was released on bail of 10,000 Egyptian pounds (A$ 2,300) late on Thursday.
Speaking on Al-Jazeera after his release, Mr Abdel Ghani said the prosecutors who had questioned him had acted "professionally" and "honestly".
He thanked the hundreds of Egyptians, including parliamentarians and journalists, who he said had supported him.
He added the reports he had sent from Dahab had been similar in content to that published by the Egyptian and foreign media.
Mr Abdel Ghani recounted earlier that he had been "almost kidnapped" and spirited away to the capital while he was in Dahab covering the aftermath of Monday's suicide bombings that killed at least 18 people.
Police fired on
Al-Jazeera - the most widely watched pan-Arab news channel - has not shied away from broadcasting topics that are sensitive in Egypt.
On Wednesday it reported policemen had been the target of an attack in the town of Belbeis, northeast of Cairo.
Other media said a police station had been fired on, quoting witnesses and security sources, but the interior ministry later issued a denial, which Al-Jazeera also carried.
The Qatar-based channel also aired a political show on Wednesday evening which was critical of the government's treatment of two judges who went before a disciplinary board on Thursday for accusing the judiciary of helping to rig parliamentary elections.
Al-Jazeera has given air time to reformist Egyptian judges who have criticised the regime and are demanding more independence from the executive.
Al-Jazeera has also aired a programme on revolutionary poets such as left-wing author Ahmed Fuad Najm, whose works are sometimes used a rallying for movements opposed to the Egyptian regime.
Union complains
Five other Egyptian journalists have been detained since Wednesday in connection with demonstrations of support for the two judges facing disciplinary action.
The journalists' union complained the arrests were against the law and rights groups have condemned Mr Abdel Ghani's detention.
"We consider the arrest of the head of the Al-Jazeera bureau to be an
attack on press freedom in Egypt," renowned columnist Gamal Fahmy said.
"For years the journalists' union has been demanding the abolition of laws restricting press freedom, including the legislation under which Mr Abdel Ghani faces prosecution."
The Egyptian Organisation for Human Rights demanded the journalist's immediate release, saying it showed the extent of the "deterioration of the conditions of freedom of opinion and expression".
The Arab Committee for the Defense of Journalists issued a similar call, saying the manner in which Abdel Ghani was "kidnapped is violation of basic human rights principles".