Complex sentence: Beginning from 2009, the government of Azerbaijan suspected that Gurbanov was working undercover for American diplomats, but, prior to Wikileaks, they could not produce any evidence to incriminate Gurbanov.
Split into simpler sentences: Beginning from 2009, the government of Azerbaijan suspected that Gurbanov was working undercover for American diplomats. Prior to Wikileaks, however, the government of Azerbaijan could not produce any evidence to incriminate Gurbanov.