A sessions court in Maharashtra's Washim on Tuesday directed police investigation against NCP leader Nawab Malik under Scheduled Caste and Scheduled Tribes (Prevention of Atrocities) Act (SC/ST Act) for making allegations about the authenticity of caste certificate of IRS officer Sameer Wankhede [Sanjay Shankarrao Wankhede vs Navab Mohd. Islam Maliq].