There’s no evidence in this article, just an allusion:

To date, he [Putin] has been able to preserve Europe’s dependence by paying bribes to leaders in many of the leftist and green parties to keep their governments from developing their own gas and oil resources (according to knowledgeable and reliable European sources that I have spoken with). The French and Bulgarian governments even went so far as to ban fracking, despite having substantial gas reserves that could make them energy independent.

http://www.washingtontimes.com/news/2014/may/5/rahn-no-western-counter-to-russias-ukraine-gambit/