A senior Russian security official said on Thursday that Russia's navy and air force had expelled a British warship from what he described as Russian territorial waters near Crimea in October, but Britain said the report was "categorically untrue".
Vladimir Kulishov, first deputy head of the FSB security service, said Russia had told HMS Dragon, a type 45 destroyer, not to enter its waters, but that it had crossed what he said was the border on Oct. 13 near southern Crimea.
Russia annexed the Black Sea peninsula of Crimea from Ukraine in 2014, drawing sanctions and condemnation from the West. Kyiv wants the territory back.
"The warship was driven out into neutral waters by the joint action of the Russian navy and air force," Kulishov was quoted as saying by Russia's RIA news agency
In an interview, he said HMS Dragon had invoked the right of "innocent passage," a concept which allows ships to transit the territorial waters of foreign coastal states in a manner not prejudicial to their peace, good order, or security.
Kulishov told RIA Moscow had demanded the vessel immediately leave its waters, to which the warship's captain replied there was poor signal reception.
Britain's Ministry of Defence denied the report, which comes as Russia's relations with the West languish at post-Cold War lows. It did not give further details.
"The Russian Federation Navy did not impede HMS Dragon's passage. She navigated without incident, exercising our right of innocent passage under the UN Convention on the Law of the Sea," an MOD spokesperson said.
"HMS Dragon was taking the most direct route between two port visits, navigating a recognised safe route for all international shipping within Ukrainian waters."