Pope Benedict XVI issued a decree on Monday allowing cardinals to bring forward a conclave to elect his successor, as the resignation of a top cardinal and deepening intrigue in the Vatican overshadowed the run-up to the vote.
"I leave the College of Cardinals the possibility to bring forward the start of the conclave once all cardinals are present," the pope said, who steps down on Thursday.
The conclave is traditionally held between 15 and 20 days after the papal seat becomes vacant although that period normally includes nine days of mourning for a deceased pope.
Swirling intrigue has overshadowed the run-up to the conclave and campaigners are calling for cardinals implicated in cover-ups of child sex abuse scandals to be barred from voting.
Cardinal Keith O'Brien, Britain's most senior Roman Catholic cleric, resigned Monday in the wake of allegations of inappropriate behaviour and said he would not take part in the conclave.
Vatican spokesman Federico Lombardi said the cardinals, who will begin a series of meetings to discuss the upcoming conclave on Friday, could settle on a date "in the very first days of March".
The Vatican revealed meanwhile that a report into a series of damaging leaks of confidential papal papers last year had revealed "imperfections" in the Catholic hierarchy.
The report "made it possible to detect, given the limitations and imperfections of the human factor of every institution, the generosity and dedication of those who work with uprightness and generosity in the Holy See," a Vatican statement said.
"The Holy Father has decided that the documents, which only he has seen, will be exclusively available to his successor," Lombardi told a press conference.
Italian media reports had suggested that cardinals set to elect a new pope would be given access to the December report.
Benedict met with the report's authors -- Julian Herranz of Spain, Slovakian Jozef Tomko and Italian Salvatore De Giorgi -- on Monday, Lombardi said.
The three cardinals -- all over 80 and thus not entitled to vote in the conclave -- questioned dozens of Vatican officials, both laypeople and clergy, in parallel with a police probe.
The Vatican hinted the cardinals could discuss their findings with other cardinals, although the report itself would remain secret.
The meeting came just three days before Benedict steps down following his shock resignation announcement on February 11.
The 85-year-old German pope cited his age as the main factor in his nearly unprecedented decision, but observers said Vatileaks may have been the last straw in a scandal-ridden papacy.
Already four other members of the conclave, now to number 115, are associated with the paedophile priest scandals that have dominated Benedict's eight years on the papal throne.
The Vatican's Secretariat of State -- the government of the Catholic Church -- took the unusual step on Saturday of issuing a statement slamming "completely false news stories" as an attempt to influence the secret conclave.
Italy's Panorama news weekly and the Repubblica daily had said on Thursday that the cardinals' report to the pope contained allegations of corruption and of blackmail attempts against gay Vatican clergy, as well as favouritism based on gay relationships.
Lombardi on Saturday dismissed the media reports as "gossip, disinformation and sometimes calumny".
In a statement on Vatican Radio's website, Lombardi said: "There are people who are trying to take advantage of this moment of surprise and disorientation of weak souls to sow confusion and discredit the Church and its government."
The investigating cardinals presented the pope with their final report in December, just before Benedict pardoned his former butler Paolo Gabriele, who had been jailed for leaking the papal memos, while banishing him from the Vatican.
Suspicions linger that more people were involved.
A Vatican communications aide, Greg Burke, said in an interview published Monday that the media "could try" to influence the conclave, adding that "some can be truly odious".
The pope is due to hold his final public farewell in St Peter's Square on Wednesday and will step down on Thursday as leader of the world's 1.2 billion Catholics.