Nazis tried the old "infiltrate the Vatican with spies disguised as monks and priests" trick

It seemed like a good idea at the time. According to the Daily Telegraph:

Officials in Germany thought the idea of agents posing as monks and priests in a cloister would be the perfect cover for them.

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.

The plan may have worked if the Nazis had paid closer attention to certain obvious details:

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 knowledge on Catholic doctrine - and their interest in women.