Steele's expertise on Russia remained valued, and he served as a senior officer under John Scarlett, Chief of the Secret Intelligence Service (MI6), from 2004 to 2009. Steele was a counterintelligence specialist&lt;ref name="Harding_Sabbagh_11/1/2019"&gt;&lt;/ref&gt; and was selected as case officer for Alexander Litvinenko and participated in the investigation of the Litvinenko poisoning in 2006. It was Steele who quickly realised that Litvinenko's death "was a Russian state 'hit. Twelve years later Boris Karpichkov alleged that Steele himself was included in a hit list of the Russian Federal Security Service, along with Sergei Skripal who was poisoned in 2018 by a binary chemical weapon Novichok in Britain.