AN AMERICAN TOURIST is in hot water with Italian authorities after he fell into the crater of Mount Vesuvius while trying to retrieve a phone he dropped while attempting to take a selfie.

The 23-year-old and his family reached the 1,281m-high summit of the iconic volcano overlooking the bay of Naples by bypassing a visitor turnstile and walking along an out-of-bounds path.

Reports in Italian media say he then dropped his phone while taking a photograph of himself and it fell into the mouth of the volcano.

The tourist then attempted to collect the dropped device by descending into the crater, only to fall several metres after losing his balance.

A mountain rescue helicopter was dispatched to the scene and Vesuvius guides abseiled into the crater to pull out the hapless hiker.

After the successful mission the man was treated for minor injuries including cuts and bruises on his arms and back.

The wayward wanderer and three of his relatives now face charges after being reported by police for the invasion of public land.

The group reportedly took a path that was clearly signposted as being forbidden due to being extremely dangerous.

Mount Vesuvius is the site of perhaps the most famous volcanic eruption in history. The extraordinary disaster in 79 AD destroyed the towns of Herculaneum, Stabiae, and Pompeii.

Vesuvius is still considered to be among the most dangerous volcanoes in the world due to its proximity to Naples and other nearby towns.