One of Russia's key tools that are yet to see confirmed action in Ukraine are £18,500 spy gadgets called 'Sphera'.

These 'robo-balls' which look like the BB-8 droid from 'Star Wars' have been battle-tested in Syria where they were used to gain secret intelligence.

They can be tossed into dense combat areas or 'trouble zones' and, using four video cameras with a 360-degree view, gather pictures and audio to be sent to military operatives up to 50 metres away.

The robo-balls also have LED lights as well as a microphone and transmitter to send radio signals.

They can operate in temperatures as cold as minus 20 C or as hot as +45 C, and are designed to be effective in street battles in urban war zones.

The Sphera were reportedly first put into action in 2018 in Syria, where Russia gave military support to the Assad regime. There, it is estimated that Russian air strikes killed around 6000 members of ISIS.