depot

"The most effective sanctions – the ones that work the fastest – are the fires at Russia's oil refineries, its terminals, oil depots," the Ukrainian leader said in a September address.

In recent months Ukrainian strikes have reached deeper into Russian territory, hitting refineries, fuel depots and logistics hubs hundreds of miles from the frontlines.

So Welch limits its three eHGVs to regional excursions within about two hours of the main depot - a radius of 160km.

A search expedition discovered their last camp just 11 miles from a resupply depot that would have provided them with food and fuel.

The helicopter was "likely not refuelled at a fuel depot" during the journey to harvest crocodile eggs, and "the pilot did not identify the reducing fuel state", investigators said.