A two-and-a-half year corruption trial that exposed infighting and intrigue in the highest echelons of the Vatican is closing with the key defendant, an Italian cardinal, praying that the court will believe his innocent plea.

Cardinal Angelo Becciu, 75, a one-time Vatican power broker, is charged with embezzlement, abuse of office and trying to induce a witness to give false testimony.

Becciu, the most senior Vatican official ever to be charged with financial crimes, has denied all wrongdoing, as have the other nine defendants.

The panel of three lay judges of the Vatican’s criminal court is expected to issue verdicts late on Saturday afternoon.

The trial, played out in 85 hearings, revolved mostly around a messy purchase of a building in London by the Secretariat of State, the Vatican’s key administrative and diplomatic department.

Becciu held the number two position there in 2014 when it began investing in a fund managed by Italian financier Raffaele Mincione, securing about 45 per cent of the building at 60 Sloane Ave.

In 2018, by which time Becciu had moved to another Vatican job, the Secretariat of State felt it was being deceived by Mincione and turned to another financier, Gianluigi Torzi, for help in squeezing Mincione out and buying the rest of the building.

Torzi also fleeced the Vatican, according to prosecutors, who have charged both men with fraud, corruption and embezzlement.

An embarrassed Vatican sold the building last year, taking an estimated loss of about 140 million euros ($A228 million).

Becciu, who was fired by Pope Francis from his second job in 2020 for alleged nepotism but who remains a cardinal, has also been accused on charges related to tangential parts of the investigation.

The cardinal is accused of funnelling money and contracts to companies or charitable organisations controlled by his brothers on their native island of Sardinia.

Another accusation involves his hiring of Cecilia Marogna, a self-styled security analyst, as part of a secret project to help win freedom for a nun who had been kidnapped in Mali.

Marogna, 46, received 575,000 euros from the Secretariat of State in 2018-19, which prosecutors say she mostly spent on luxury purchases for herself.

The other six defendants include the former president and director of the Vatican’s Financial Intelligence unit, the cardinal’s former secretary, and three former Vatican employees.

-AAP