The consumer rights agency Rospotrebnadzor found "non-compliance with sanitary and hygienic standards in sand and seawater samples" in Anapa and the Temryuksky District of the Krasnodar Region, a traditionally favoured destination for summer holidays in Russia.

More than 2,000 tonnes of oil products were released into the Black Sea after two ageing tankers sank in a heavy storm on December 15 in the Kerch Strait, between Moscow-annexed Crimea and the southern Russian Krasnodar region.

The spill has sparked an environmental disaster, harming many marine animals and birds.

With concern over the incident mounting, Russian President Vladimir Putin was shown being briefed on the spill response by a government official in a video released by the Kremlin on Monday.

Thousands of volunteers have flocked to the region to help clean up beaches and rescue animals caught up in the spill.

Government agencies had put the costs of the oil spill at almost $1 billion.

With Russians facing international travel restrictions since Moscow began its military offensive in Ukraine, Anapa hosts an ever-growing number of tourists, welcoming 5.5 million people last year.

Under Western sanctions, Russia has resorted to using a so-called "shadow fleet" of mostly old tankers to export its fuel around the world.

An investigation by Russia's transport watchdog found that the main reason for the spill was that the vessels were not certified to sail in that area of the sea at that time of year.