The National Investigation Agency has summoned Shivam Dhakad, an associate of murdered former Rashtriya Swayamsevak Sanch pracharak Sunil Joshi, to New Delhi for questioning.A team of the NIA is currently probing the killing of Joshi and Shivam has been summoned in this connection, officials said. Shivam, who is a resident of Dewas in Madhya Pradesh, was recently released on bail. He is also an accused in the murder of Kok Singh Solanki, a village sarpanch.