Researchers are being given the long-waited opportunity to peer into the pontificate of Pope Pius XII as the Holy See opens up its archives on the controversial figure. 

Pius XII was Pope from 1939, the same year World War II began, until his death in 1958.

He remains as divisive today as he was then, with critics branding him an anti-Semite and "Hitler's Pope", while others argue that his behind-the-scenes efforts to save Jews from the Nazis have been overlooked. 

Now scholars are being given the opportunity to delve into the Vatican Apostolic Archives and shed new light on the wartime Pope with thousands of documents being made available to them for the first time. 

Only a Pope can made the decision to open up the archives relating to another pope. The decision to unseal the archives on Pius XII was made last year by Pope Francis. 

The documents are being made available to around 120 researchers at a time by reservation only. 

"The goal of opening up the archives on Pius XII is to give scholars the possibility of accessing sources that were unavailable up until now," Vatican News said.