Abdul Merhi, 50, was one of four men taken into custody on Saturday when five Sydney properties were raided by NSW and federal police.
Authorities became aware of an alleged plot to "bring down" a plane using a home-made device and detained the men without charge under terror legislation.
Mr Merhi was released about 7pm Tuesday and his solicitor, Moustafa Kheir, said he endured days of intense questioning.
"It's a very serious allegation to have against you," he told AAP on Wednesday.
"There's a lot of stress associated there, and not knowing, and he was shocked that he was being questioned.
"It's just unfathomable that he would be associated with anything like this."
Mr Merhi's family was also in shock and his life had been "turned upside down", Mr Kheir added.
"He just wants to go back to as normal life as possible now."
Mr Kheir said he would review the actions of police.
"A lot of information was divulged, including his identity," he said.
"That's caused a lot of damage to him. We want to review all the information police had and what basis they had to do what they did."
The three other men can be detained until Sunday evening under the terror legislation.
Federal police have spent days rifling through several properties across Sydney following the weekend raids in Surry Hills, Wiley Park, Lakemba and Punchbowl.
The other three men remain in custody under special powers which allow police to hold them for up to a week.
"This investigation remains ongoing, and further information will be provided at an appropriate time," a joint statement from the AFP and NSW Police said on Wednesday.
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The alarming plot is reported to have allegedly involved an improvised device and the target was a plane, with one theory suggesting the would-be terrorists planned to use a meat grinder to conceal their home-made device.
Meanwhile, Etihad Airways on Tuesday confirmed it was helping Australian authorities with the investigation amid reports the arrests were made after a tip-off from foreign intelligence services.
News agency Reuters cited a US official as saying the plot was "fairly well along".
Police have until Sunday to charge the men before they are released, however, it's understood detectives might be able to apply for further detention provisions.
Huge queues at Sydney Airports T2 Domestic Terminal as passengers are subjected to increased security, Sydney, Australia, Monday, July 31, 2017. (AAP) Source: AAP
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