Vatican police have raided a Cardinal's apartment where a drug-fuelled homosexual orgy was taking place, leaving Pope Francis infuriated, according to reports.

It has emerged that police last month entered an apartment at the former palace of the Congregation for the Doctrine of the Faith, whose responsibilities include investigating clerical sexual abuse.

The occupant of the apartment is alleged to be a priest who serves as a secretary to Cardinal Francesco Coccopalmerio, who is the head of the Pontifical Council for Legislative texts and a personal adviser to the Pope.

When police arrived at the apartment, they reportedly found drugs and a group of men engaged in sexual activity.

The priest was reportedly arrested and taken for questioning, presumably over drugs offences, as engaging in homosexual sex is not a crime in Vatican City.

According to the Italian daily newspaper Il Fatto Quotidiano, neighbours became suspicious before complaining about the irregular behavior of those who were coming and going at the apartment.

Il Fatto Quotidiano claimed that Pope Francis has been infuriated by the news and may force Coccopalmerio into retirement.

The revelation comes a week after Cardinal George Pell, appointed by the Pope to clean up the Vatican's finances, took leave of absence to defend himself against sex abuse charges in Australia.

Pell, 76, has protested his innocence and claimed that he was looking forward to having his day in court after a two-year investigation, 'leaks to the media' and 'relentless character assassination'.

Australian police have not revealed details of the charges against Pell, citing the need to preserve the integrity of the judicial process.

In March, the Vatican was also hit by claims of separate orgies and prostitution among priests across Italy.