Who is Sergey Kislyak, the Russian ambassador at the heart of a massive global controversy?

Sergey Kislyak - Russia's convivial Ambassador to Washington - has been in the eye of a media storm since it emerged that members of the Trump administration had undisclosed meetings with him in the run up to the 2016 US election. Kislyak is a career diplomat, having spent 35 years working for the Soviet and Russian governments.

He has previously kept a low profile, favouring lavish dinners over media appearances to get his message across. But the recent controversy over the Trump administration's relationship with Russia has forced him into the spotlight.

Mark Coles speaks to people who have worked with him and followed his career to get under his skin and find out where his career might go now that he's become such a controversial figure.

Producer: Ben Crighton.