The first photographs have been released of Benito Mussolini's secret wartime bunker under his Rome headquarters in Palazzo Venezia, three years after it was rediscovered.

The 80-sqm reinforced concrete bunker lies between 15 and 20m below ground level, exposing some still-visible ancient Roman remains.

It was rediscovered in late 2010 during maintenance work on the building's foundations by Rome’s cultural heritage department. Officials came across a wooden trap door that revealed a brick staircase leading to the nine-room bunker.

Although the ventilation system is functional, the dirt floors and unfinished electrical and drainage networks reveal that the bunker's construction was not completed prior to Il Duce being forced from power in Rome in 1943.

Under increasing fear of Allied attacks, Mussolini ordered the bunker's construction at the end of 1942, around the same time that a much more elaborate bunker was built under his private Rome residence, Villa Torlonia on Via Nomentana.

Last year the Villa Torlonia bunker was opened to the public, and the city has similar plans to open the Palazzo Venezia bunker to visitors later on this year.