A dark past has been unearthed at a Hamburg sports club, where builders have discovered a giant stone swastika buried near the site of a new locker room facility.

Construction work is underway at Billstedt-Horn football and athletics club, which predates World War I. But a forgotten symbol of Germany’s notorious National Socialist Party government of the 1930s has hampered the laying of new building foundations at the site.

Last Friday, an excavator unexpectedly hit rock – which was later found to be a giant swastika. The infamous emblem was co-opted by the Nazi party and embraced by Adolf Hitler.

The area was once the location of a Nazi-era monument, according to Billstedt-Horn Chairman Joachim Schirmer. He told Der Spiegel that the statue had been torn down decades ago.

Footage from the area reveals the 13ft by 13ft swastika located between houses and a running track. German authorities have been informed, reports Bild. The swastika is expected to be destroyed on site – machinery has been unable to remove the stone structure because of its size and weight.