Moussa Hamka claimed he was paid by an unknown person on a messaging app to hide the gun used to shoot five people outside Melbourne's Love Machine nightclub.
When police searched his house in June 2019, about two months after the shooting, he took officers to a semi-automatic pistol wrapped in a T-shirt under his bedside table.
He told police he had answered a message on encrypted app Wickr from someone he did not know, who offered to pay him $3000 to collect a package and hold it for safekeeping.
But Supreme Court Justice Andrew Tinney rejected this story as "exceedingly far-fetched" as he sentenced Hamka to six years in jail for concealing the weapon used by his friend, Love Machine nightclub shooter Jacob Elliott.
Richard Arow and Aaron Osmani died and three others were injured when Elliott, driven by Allan Fares, fired five shots at the Little Chapel St nightclub in Prahran on April 14, 2019.
The shooting was sparked by club security's decision to eject Elliott's younger brother from the club for poor behaviour.
"These were two murders carried out in heartless and outrageous circumstances in a public display of vengeance," Justice Tinney told the court on Wednesday.
"This weapon, which you saw fit to hide in your home, was to your knowledge a highly important exhibit keenly sought by the police in connection with the notorious and heinous crimes committed by your friends at Love Machine.
"By your actions, you sought to assist your friends to avoid apprehension, and in doing so, to deliberately frustrate the substantial police investigation you knew to be going on."
Hamka was at Elliott's father, Nabil Maghnie's, Docklands apartment when his son Ali Maghnie visited after being ejected from the nightclub in the early hours of April 14.
While Hamka had no involvement in the shooting, Justice Tinney said he knew of the family's "unhappiness" about Ali's expulsion.
Elliott and Fares were last month sentenced to life in prison after being found guilty of murder by a jury in April, who also found Hamka guilty of assisting by concealing the murder weapon.
After the trial Hamka pleaded guilty to an additional charge of being a prohibited person possessing a firearm.
Justice Tinney found Hamka had the murder weapon in his possession for a significant period before his arrest.
"Your crime was a serious one and certainly not a low-level example of the offence," he said.
"The sentence I pass must bring it clearly home to any person who might be minded to provide assistance to others in the aftermath of their serious crimes that such conduct will be met with strong punishment."
One year and one month of pre-sentence detention was included in Hamka's six-year prison term.
He must serve four years before becoming eligible for parole.
