Jail cells. For illustrative purposes only. Image Credit: Agency

Vatican City:  A Vatican court has ordered an Italian businessman jailed for money laundering, a first for the notoriously secret micro-state.

The court ordered Angelo Proietti, 63, jailed for two-and-a-half years, and seized more than a million euros ($1.14 million) that he deposited in an account at the IOR or Vatican bank.

The account has been frozen since the case began in 2014.

Proietti is on trial in Italy for bankruptcy fraud, and was accused of illegally siphoning money from his business to his Vatican account.

He is under house arrest and can appeal the sentence. He would not serve time in the Vatican itself but in an Italian prison as the Vatican only has holding cells.

"This is the first time that this crime has been prosecuted in Vatican jurisprudence," the seat of the Roman Catholic Church said in a statement Thursday about the December 17 sentence.

The IOR has 15,000 clients, most of whom have connections with the Catholic Church, and manages around 5.7 billion euros in assets.

The Vatican's bank made headlines following the 1982 death of Roberto Calvi, known as "God's banker" because of his links to the Holy See, whose corpse was found hanging from Blackfriars Bridge in London.

Prosecutors believe it was a mafia killing linked to money laundering via the bank.

That and other scandals prompted a clean-up in recent years, first under Pope Benedict XVI and then under the current pontiff Pope Francis, with about 5,000 bank accounts closed.