SOURCE: Telegraph (UK) (3-15-10)
A Nazi sympathiser living in Rome came up with the idea and it was quickly seized upon by officials in Berlin who saw it as the ideal opportunity to keep up with Allied activity in the city.
The plan is revealed in MI5 reports held at the National Archives in Kew and which have now been declassified - and it comes just days after other files revealed how Germany had also tried to infiltrate the Boy Scouts.
Operation Georgian Convent as it was called involved the purchase of a building in Rome by Michael Kedia, a Russian anti communist Nazi sympathiser from Georgia (Russian Republic of) who was also known to British intelligence.
According to the documents at Kew the idea gathered pace in the Autumn of 1943 as the Allies advanced up through Italy and the Germans were preparing to pull out of Rome.
MI5 was tipped off about the plan by Giuseppe Dosi, an Italian policeman who was acting as an informant to the British intelligence service and his report is in the file.
It reads how a "....plan was started whereby the immunity of the Vatican buildings in Rome was to be exploited to the advantage of the German Intelligence Service.
"The plan (involved the)...set up a Georgian cloister in Rome under Vatican protection and among the monks introduce agents who were to keep contact with German intelligence."
Dosi's report added how two rooms within the cloister were to "be set aside for the use of the agents for storage of transmitters, batteries and any other secret material."
Officials in Germany thought the idea of agents posing as monks and priests in a cloister would be the perfect cover for them and enable them to covertly carry out spying work as during the war the Vatican remained neutral.
Money was provided from Germany and a building to be used as the Georgian cloister was bought by Kedia in the Monteverde district of Rome, just to the north of St Peter's.
Six agents were sent to the cloister to pose as monks and seminarians but they aroused the suspicion of Vatican officials for their lack of knoweldge on Catholic doctrine - and their interest in women.
However, the plan was thwarted after a tip off to the Vatican who wrote a letter to Germany's Ambassador for the Holy See saying it had been informed of the plot and "deplored" by it.