Billionaire investor Rakesh Jhunjhunwala is being probed by Sebi for alleged insider trading in the shares of Aptech Ltd, an education firm owned by him and family, said two people familiar with the development. The markets regulator is also investigating the role of other family-members who are shareholders, as-well-as some board members, including investor Ramesh S Damani and director Madhu Jayakumar, the persons added.