Last year Dr Sidharth Kaushal, from the Royal United Services Institute, told The Mail on Sunday he believed the fleet of unmanned underwater vehicles (UUVs) could be of strategic value for President Putin. Dr Kaushal said: 'The Belgorod is large enough to act as a mother ship for a unique set of smaller vessels which have deep-diving capabilities and the ability to tamper with undersea infrastructure. 'It's well equipped for sabotage and clandestine operations. Its Poseidon nuclear torpedoes could also be a very effective means of attacking an aircraft carrier in wartime – one against which at present no defence exists. 'The Belgorod will not be part of the Russian Navy per se, meaning its covert and aggressive actions will effectively be deniable. 'The submarine appears set up for non-attributable Special Forces warfare with its commanders answering directly to the [political] leadership and bypassing the Russian naval command structure.'