American tour guide exposes terrorism risk at Colosseum.

A video published by Italian newspaper La Repubblica on 31 May reveals a major flaw in the security system in place at the Colosseum.

The flaw involves an internal barrier, in the section for visitors without reservations, through which objects can be passed to those who have already gone through security checks and metal detectors.

The weak link in the monument's system was highlighted weeks ago by American tour guide Rich Brunn – both to Colosseum authorities and the police – but so far nothing has been done to remedy the situation.

The video by La Repubblica shows the ease with which a reporter was handed a plastic bag containing a bottle of liquid and a household metal object, which she carried throughout the monument, even leaving it unattended among tourists on the arena's top floor.

The discovery comes a week after a major security operation in the capital for the visit of US president Donald Trump, and two days ahead of the city's Festa della Repubblica celebrations.