This was the dramatic moment a Russian nuclear sub was spotted off the coast of Norway after being shadowed by the RAF’s ‘submarine hunter’, a Poseidon P-8 patrol aircraft.

The Akula (shark) class vessel was initially submerged as the British air patrol and a fleet of Norwegian naval warships kept track of its movements beneath the waves.

his particular tense stand-off came to an end when the Russian sub headed out into the North Sea.

The photographer, who we haven’t named, said he got the impression that the NATO ships forced the Russian sub to the surface, but a leading expert contacted by MailOnline doubted that.

Sidharth Kaushal , Research Fellow (Sea Power) at the Royal United Services Institute (RUSI) confirmed the vessel was an akula class nuclear attack submarine.

He said: ‘I think that’s very unlikely it was forced to the surface, as they can only really do that with depth charges.

‘It’s a cat and mouse game between these submarine patrols and the countries they are passing.

‘Submarines quite often travel on the surface as it's safer to navigate that way. This one may have been part of the Russian Northern Fleet on its way back from the Navy Day parade in St Petersburg on July 31.

‘Whatever the Russian submarine was doing there, either simple transit or something more clandestine, the Norwegians would want to shadow it with help from other NATO assets.

‘NATO officials have said that Russian submarine activity is at levels that they haven't seen since the Cold War.

‘The Norwegian vessel appears to be a Fridtjof Nansen-class frigate of the Royal Norwegian Navy involved in the operation surrounding this submarine.’

Last month, a a Royal Navy warship tracked the movements of two Russian submarines as they sailed into the North Sea in a similar area.

It’s possible the akula submarine spotted last weekend was the same one on its return from the Navy Days event.

British submarine hunter HMS Portland spotted the cruise missile submarine Severodvinsk and Akula-class attack submarine Vepr made their underwater journey south along the Norwegian coast from the Arctic.

The Type 23 frigate shadowed the submarines as they surfaced separately in the North Sea, north-west of Bergen, Norway, on July 16 and 19, before NATO and Baltic forces took over duties as they continued to St Petersburg for Russian Navy Day celebrations on July 31.

Portland and her specialist Merlin helicopter – both equipped with cutting-edge sonars, sensors and torpedoes for submarine-hunting operations – reported on the movements of the Russian Northern Fleet vessels.

One of the RAF’s P8 Poseidons, also worked closely with HMS Portland to hunt and track the submarines.