British Transport Police (BTP) are investigating if any offence was committed after panic erupted in the packed station on Friday.
Several people were injured and nine were taken to hospital, including one with leg injuries, after panic erupted in the packed Underground station on Friday.
Armed police raced to Oxford Circus Tube station and Oxford Street after receiving 999 calls reporting shots had been fired.
The two men, aged 21 and 40, were quizzed on Saturday after going to a police station voluntarily.
BTP said the incident was believed to have started when an altercation erupted between two men on the platform.
A spokeswoman for the force said: "There are no criminal proceedings against them. They have not been arrested or charged."
Officers are still trawling through CCTV footage and speaking to witnesses in an attempt to make sense of what happened, but no further suspects are being sought.
The incident sparked panic among rush-hour commuters and Black Friday shoppers in central London.
But around 90 minutes after responding, police said there was no evidence of any shots, casualties or suspects.
The station was reopened, cordons removed and the area returned to normal.
The public response to the altercation, fueled by unfounded social media posts about gunfire, indicated that Londoners remain on edge after a year marred by numerous extremist attacks.
Police initially treated the reported gunfire as a possible terrorism incident and social media was filled with alarming false reports about shooting at several locations.
The singer Olly Murs contributed to the confusion by tweeting about gunfire at the famous Selfridges department store on Oxford Street.
Some people were injured in the stampede away from the subway station. Major stores opened as usual Saturday as crowds descended in search of bargains.
Britain's official terrorist threat level is set as "severe," indicating that intelligence analysts believe an attack is highly likely.
Anyone with any information can contact BTP on 0800 40 50 40 or text 61016 with reference 405 of 24/11
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