This is the moment the Black Sea lives up to its name as large globules of black oil emerge from the seabed and float to the surface.

According to a report by local news website Smotrim, people living in the town of Tuapse in the Russian federal subject of Krasnodar Krai were the first to raise the alarm to the problem.

They noticed that there was a slick of oil on the Back Sea and a strong odour coming from it on 24th May, and when the authorities were warned they immediately swung into action.

As there was no obvious source on the surface, divers from the Ministry of Emergency Situations in Krasnodar Krai were sent in.

They then discovered that the source of the oil spill was coming from the seabed, with the oil bubbling out and floating to the surface on the morning of 25th May.

Oil leakage from the underwater sewer can be seen in the video of the work carried out at a distance of 700 metres (2,296 ft) off-shore and a depth of 10 metres (32 ft).

The city administration stated that six special ships had been drafted in to remove oil pollution and that 1,300 kilogrammes (2,866 lbs) of absorbent had already been used up in collecting oil.

Later, the head of the Tuapse district, Vitaly Mazninov, told local media that the specialists had eliminated the consequences of the oil spill.

However, images taken after still seemed to show some contamination, with fears locally for the upcoming holiday season, with oil also reportedly turning up on Tuapse city beaches.

Local news website Rossiyskaya Gazeta reported that a total of 75 people and 22 units of equipment took part in the elimination of the spill and closing off the source of the problem.

The cause of the incident has not yet been officially announced, but some reports said that the local oil refinery is old and in need of repair, and that for some time oil had been leaking into the ground, building up an underground reservoir of oil without anybody taking responsibility for it.

Eco-activist Dmitry Shevchenko said that the problem has been going on for a long time and that it was well known that there had been an underground accumulation of oil that periodically broke through to the surface.

However, the local refinery rejected the suggestion that their facility was to blame, saying instead that it was probably a deep-sea reservoir or something to do with the city sewer network.