New Delhi, Sep 20 (ANI): In a major relief to Samajwadi Party Chief Mulayam Singh Yadav, the CBI on Friday closed its investigation into a corruption case against him citing lack of evidence. This comes two months after a CBI officer recommended closing the six-year-old investigation into whether the SP chief and his son, Akhilesh Yadav, the Chief Minister of Uttar Pradesh, had accumulated wealth beyond their known sources of income. The agency says it had investigated all the assets and properties mentioned by petitioner Vishwanath Chaturvedi, who had petitioned the Supreme Court for a probe in 2007.