"The UK is actively operating in southern Ukraine, particularly in Mykolaiv, with UK aircraft regularly arriving at the Kulbakino airbase [in the city]," Prozorov said.
He also noted that the UK experts, who arrive in Mykolaiv, are constructing the naval base in Ochakiv. The UK private military company is responsible for the expert's safety, according to Prozorov.
The former SBU officer could not say the number of UK experts and officers of the private military company deployed in Ukraine.
The latest development comes after UK Defense Secretary Ben Wallace met with NATO Secretary General Jens Stoltenberg to discuss matters brewing along Ukraine's border with Russia, which has been repeatedly accused of building up its forces in the region.
In fact, tensions between Russia and western powers have largely plummeted over the last months as a result of continued troop build-up reports. Russian President Vladimir Putin more recently weighed in on the reports during his year-end conference, blasting accusations as baseless.
Putin Warns NATO Expansion Eastward is Unacceptable: 'US Has Come to Our Doorstep With Its Missiles'
23 December 2021, 10:34 GMT
"We are not the ones who are threatening someone," Putin told the crowd of reporters. "Are we the ones who went there, to the US borders, or to the borders of the United Kingdom or somewhere? They came to us, and now they still say: no, now Ukraine will join NATO as well."
The annual news conference also saw the Russian leader discuss the European energy crisis, Russian relations with China and the recognition of the Taliban government, among other pressing topics.