During a two-year investigation that culminated in the arrest of 40 suspected mafia members on Tuesday, police in Italy secured unprecedented footage of a secret initiation ceremony held by the powerful Italian mafia and cocaine trafficking organization 'Ndrangheta.

The ceremony was reportedly held at a farmhouse in the northern Lombardy region to induct 'Ndrangheta members into an internal secret society called "La Santa." Police footage shows a speaker opening the initiation "on behalf the names of Garibaldi, Mazzini, and La Marmora" — political icons of Italian history. A small group of apparently middle-aged men standing in a circle and bowing their heads as the speaker reads rites to the new inductees, who pledged themselves "beneath the light of the stars and the splendor of the moon."

The speaker asks the men to say, in unison, "I swear to renounce everything up to the seventh generation and the entire criminal association recognized by me until now in order to safeguard the honor of my wise brothers."

The men also swear an "oath of poison," with the pledge dictating that they will each keep a "bullet reserved" in the event that they prove disloyal.

Italian authorities released the video while announcing that alleged gangsters affiliated with the organization throughout northern Italy were arrested and charged with various crimes, including illegal weapons sales and extortion.

Individuals suspected of belonging to three separate northern clans affiliated with the Calabrian 'Ndrangheta were apprehended. While the ceremony and arrests took place in northern Italy, 'Ndrangheta has its roots in the south. Authorities said the arrests confirmthat the group has boosted its operations in the north.

The investigation also uncovered notebooks describing the ceremony, which Milan prosecutor Ilda Boccassini said at a press conference had only been infiltrated by undercover officers until now.

It remains unclear how the police secured the footage, but police have acknowledged the use of hidden cameras and wiretaps throughout the investigation.