Corrections Victoria uncovered George Marrogi's plot in April 2022 after conducting targeted searches of his personal property at Barwon Prison, according to affidavits released by Victoria's Supreme Court on Thursday.
The foiled plan had advanced far enough that the underworld figure had documents containing private information about prison staff, their families, a judge, a tax invoice for a yacht and aerial images of certain units inside the prison.
"These documents, together with intelligence information collected by CV, indicated that the plaintiff had been conspiring via unmonitored legal calls to escape prison using a helicopter," assistant commissioner for sentence management Jennifer Hosking said in an affidavit.
"The design drawings and tax invoice for the yacht indicated that a yacht was intended to be involved in the escape plans."
The affidavit claimed Marrogi had spoken about various ways to escape, including having associates extract him by force during an escort, using a helicopter and bribing a Corrections Victoria staff member to have him released from custody through an "administrative error".
Marrogi, 36, is serving a 32-year prison sentence for drug trafficking and the shooting murder of Kadir Ors in 2016.
Affidavits from prison staff detail Marrogi's extensive criminal history and his conduct while in custody, including multiple threats and assaults against prison officers.
The documents were released as Marrogi attempts to improve prison conditions, by suing the Department of Justice in a bid for greater freedom while in custody.
Marrogi claimed during his civil trial, when it began in September, that the prison yards he's been confined to have been cleaned only once in nine years.
His barrister Sarala Fitzgerald alleged prison staff had restrained and controlled his daily experiences, from human interaction to seeing the natural world.
Ms Hosking told the trial Marrogi was separated in September 2016 due to the nature of his alleged offending, the victim's associates and the media attention.
She said he was regularly and randomly moved from cells due to his high escape risk.
Closings in Marrogi's trial continue in the Supreme Court.
