OAS officer Suraraj Sadashya, posted as the Tahasildar, Sukuruli, Dist-Mayurbhanj, allegedly demanded an illegal gratification Rs 15,000 from one S K Mirazul of Tato, village under Karanjia police station area in Mayurbhanj district, for release of his metal-laden truck, which was interpected by the Tahasildar since September 27, official sources said here.