The snap rally on October 9 was sparked by a decision to light the Opera House's sails in the colours of the Israeli flag after the Hamas attack that sparked the latest Israel-Gaza conflict.
Edited footage of protesters chanting "gas the Jews" was later shared by the Australian Jewish Association with news organisation, leading to widespread condemnation and changes to hate-crimes laws.
But NSW Police, which had come under fire for not intervening, said an extensive investigation found no evidence the chant occurred at the rally.
"As a result of independent forensic analysis of audio-video files of the demonstration provided to investigators, police have no evidence that this phrase was used," investigators said in a statement on Friday.
"Police also obtained statements from several individuals who attended the protest indicating they heard the phrase, however, these statements have not attributed the phrase to any specific individual."
Mal Lanyon says forensic experts found no evidence the chant was used. (Bianca De Marchi/AAP PHOTOS)
Deputy Commissioner Mal Lanyon said there were offensive words used at the protest, but analysis from a forensic expert showed the statement that was "overwhelmingly used" was "where's the Jews?".
Several protesters at the rally held signs criticising Israel and its government, including descriptions of the nation as a terrorist state.
Detectives continue to ask anyone with information who may not have yet spoken with police to come forward.
Australian Jewish Association president David Adler told AAP he was unable to immediately comment as he had not seen the police statement.
Many pro-Palestinian activists and Arab elders said they were disgusted by the actions at the rally. (Dean Lewins/AAP PHOTOS)
At the time of the protest, Premier Chris Minns led a host of prominent figures condemning the rally and the "shocking and abusive" comments reportedly made there.
Opposition Leader Mark Speakman also criticised police for approving the march and warning the Jewish community to steer clear of the Opera House forecourt.
"This was meant to be a chance for our Jewish community to have a peaceful vigil ... and instead it's allowed to be hijacked by a rowdy mob shouting anti-Semitic slogans, lighting flares and burning a flag," he said.
Protest organisers Palestine Action Group previously rejected claims "gas the Jews" was uttered at the protest, while attributing a similar comment - "f*** the Jews" - to a tiny fringe of "vile anti-Semitic attendees".
The mostly young teens were quickly condemned and asked to leave, the organisers said, with longstanding pro-Palestinian activists and Arab elders "disgusted and deplored by the action".
The ugly scenes were preceded by dozens of peaceful pro-Palestine demonstrations across the nation, including several attended by thousands of people in Melbourne and Sydney.
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