Few passing London tourists would ever guess that the premises of Bulgari, the upmarket jewellers in New Bond Street, had anything to do with the pope. Nor indeed the nearby headquarters of the wealthy investment bank Altium Capital, on the corner of St James’s Square and Pall Mall.

But these office blocks in one of London’s most expensive districts are part of a surprising secret commercial property empire owned by the Vatican.

Behind a disguised offshore company structure, the church’s international portfolio has been built up over the years, using cash originally handed over by Mussolini in return for papal recognition of the Italian fascist regime in 1929.

Since then the international value of Mussolini’s nest-egg has mounted until it now exceeds £500m. In 2006, at the height of the recent property bubble, the Vatican spent £15m of those funds to buy 30 St James’s Square. Other UK properties are at 168 New Bond Street and in the city of Coventry. It also owns blocks of flats in Paris and Switzerland.

The surprising aspect for some will be the lengths to which the Vatican has gone to preserve secrecy about the Mussolini millions. The St James’s Square office block was bought by a company […]