Jailed Cardinal George Pell could be asked to give evidence to a Vatican inquiry into alleged irregularities in real estate investments made by a powerful church office.
Vatican investigators are examining evidence seized over investments dating back to 2012 allegedly using funds donated by Catholics worldwide for the Pope's charities.
As head of the Secretariat for the Economy, Pell was given the job of cleaning up the Vatican's finances from 2014 until he stood aside in 2017 to fight sex abuse charges.
The investigators could ask Pell, who is behind bars in Melbourne after being convicted of sexually abusing two choir boys, to give evidence.
Italian weekly magazine L'Espresso reports Pell's office was bugged by head of Vatican police Domenco Giani and that the Vatican's Secretariat of State was speculating in real estate with the Pope's charity funds.
Two weeks ago Vatican police seized documents and computers in the Secretariat of State, the most important Vatican office, and also in the Vatican financial Information office which fights money laundering.
Italian media reports say prosecutors believe they have found "serious indications of embezzlement, fraud, abuse of office, money laundering and self-money laundering."
Five Vatican officials have been suspended - four lay employees and Monsignor Mauro Carlino, who heads the Secretariat of State's Information and Documentation office.
The Vatican Promoter of Justice ordered the seizures following complaints by the Institute for the Works of Religion, often mistakenly called the Vatican Bank.
Italian media outlets say its complaints relate to the Secretariat of State approving about 200 million euros ($A326 million) for investment in a 17,000 square metre luxury apartment conversion of a former Harrod's warehouse in London.
The reports say 45 per cent of the site was bought in 2012 and the remaining 55 per cent was approved for purchase by Secretariat of State official Alberto Perlasca in November 2018, after Pell had stood aside.
In February 2014, Pope Francis created a Secretariat for the Economy to oversee Vatican finances, gave it the same status as the Secretariat of State and appointed Pell as its Prefect.
Soon after his appointment Pell annoyed the Secretariat of State when he gave an interview in which he disclosed it had substantial unlisted funds.
The Secretariat of State said every Pope was informed of these emergency funds on election and believed Pell was not a good team player.
Other prelates keen to protect their own turf disliked Pell's commanding manner, while the L'Espresso called him 'an ambitious mastiff.'
As current investigations concern financial investments in place when Pell was in office, he could help the investigation.
Through the Cardinal Pell Supporters group, he has already expressed his disquiet about the current Synod of Bishops in the Vatican.
News of the latest investigation was leaked to L'Espresso which Pope Francis said was 'grave as a mortal sin' and he ordered an inquiry into who was responsible.
Pell's lawyers have lodged a special leave application with the High Court in Melbourne seeking leave to appeal his conviction.
Australian Associated Press