Argentina's Catholic Church is launching an investigation into whether a group of nuns helped a former government official who allegedly tried to hide $9 million in cash at their convent.

The four nuns will be investigated "to determine if there was a canonical crime and help the actions of the civil justice," the Rev. Tom O'Donnell, a leading member of the probe, told local radio Wednesday.

Jose Lopez, a former public works secretary, was arrested in June at the convent on the outskirts of Buenos Aires. Police discovered wads of U.S. dollars and three other currencies.

Argentine media recently aired closed-circuit TV footage showing Lopez carrying a rifle and carrying cash in through the convent's main entrance aided by two nuns.

One of the nuns is to appear before Judge Daniel Rafecas on Aug. 1. A neighbor of the monastery, who called authorities after he saw Lopez throwing bags onto the property, is also expected to appear.

After leading an inspection of the convent Wednesday, Rafecas told reporters that authorities had seized documents "showing a relationship of more than decade" between the convent and Lopez, who was in the Cabinet of President Cristina Fernandez.

Since Fernandez ended her presidential term in December, President Mauricio Macri's administration has promised to root out Argentina's endemic corruption. Analysts say that has emboldened judges who are now freer to pursue sensitive cases against Fernandez and her allies without fear of retribution.

The former president has been included in investigations involving allegations of money laundering and possible illegal enrichment.