NEW DELHI, February 27: The government today formally handed over to the Central Bureau of Investigation (CBI) investigations into the mysterious death of an explosives expert in Bilaspur, from whom documents pointing to threats to the life of Sonia Gandhi were recovered.CBI director D R Karthikeyan said, ``Our officials are already on the move.'' The CBI has been asked to investigate all aspects of the case, including the cause of death, the significance of the items found in his possession and his antecedents, he said. CBI sources said a preliminary enquiry (PE) report was being registered to formally begin the probe. On the basis of the PE, a First Information Report would be registered later.Earlier, in Bhopal, the Madhya Pradesh government recommended to the centre that a CBI probe be ordered into the mysterious death of the 26-year-old engineer in Bilaspur, who was suspected of being involved in a conspiracy to assassinate Sonia.Senior officials said the decision to recommend a CBI probe wastaken in view of the ``seriousness'' of the incident.