The collapse occurred at the House of Loreius Tiburtinus
The discovery of a newly collapsed historic column has raised concerns just weeks after UNESCO announced plans to assist the Italian government in preserving Pompeii.
The United Nations cultural agency previously accused Italy of neglecting the site when the House of the Gladiators collapsed in 2010.
It had appeared that the situation was soon to be under control, but the latest collapse has revived concerns about the gravity of the situation.
On Thursday, it was discovered that a column that once supported the wooden trellises in the House of Loreius Tiburtinus had crumbled. The nobleman's house, built in the second century BC, was once the site of extensive gardens with ornate fountains, statues and frescoes.
Archaeologists and police are working together to determine what caused the column to collapse.