Amaravati: The Andhra Pradesh government on Tuesday constituted a Special Investigation Team (SIT) to probe the adulteration of ghee used for making Tirupati laddu. Sarvashrestha Tripathi, Inspector General of Police (IG), Guntur range, will head the SIT. Gopinath Jetty, Deputy Inspector General (DIG), Visakhapatnam range, and Harshavardhana Raju, Superintendent of Police, Kadapa, are the members.