Who was Georgi Markov?

Georgi Markov, an acclaimed novelist and playwright, whose works included 'The Archangel Michael' and 'Personal meetings with Todor Zhivkov', was born in Sofia, Bulgaria on 01/03/1929.  

In June 1969, Markov obtained permission to leave Bulgaria - then a communist state run by dictator Tudor Zhivkov - on the pretext of visiting his brother in Bologna, Italy.

In 1971, he settled in Great Britain and became a broadcast journalist for BBC, Deutsche Welle and the Radio Free Europe, where he critised the Bulgarian communist party harshly.  He had a large audience in Bulgaria.

Markov received several threats and anonymous warnings, but still continued his diatribe against Zhivkov.  In 1977, the KGB was asked to have him silenced.

Georgi Markov died on 11/09/1979.  He was diagnosed with Septacemia.  It was clear that he had enemies, but did this have anything to do with his death?