The Royal Navy has been monitoring a Russian spy ship after it was spotted around UK waters earlier this week, the defence secretary has told MPs. John Healey said the vessel, Yantar, was used for gathering intelligence and mapping the UK's critical underwater infrastructure.

The Royal Navy of the United Kingdom has been closely tracking a Russian spy ship recently spotted in British waters, sparking concerns about Russia’s activities near the U.K.’s critical underwater infrastructure.

Defence Secretary John Healey said Russia "remains the most pressing and immediate threat to Britain", and added that "any threat will be met with strength and resolve".