Former Uttar Pradesh chief minister and Samajwadi Party chief Akhilesh Yadav could be investigated for his role in the sand mining case, CBI sources said on Saturday. Mr Yadav held the mining department between 2012 and June 2013. A senior agency official said that all mining ministers in the state in between 2012 and 2016 will be questioned. Former UP minister Gayatri Prajapati, who succeeded Akhilesh Yadav as mining minister, is also likely to be summoned by the CBI.