Penetration, however little, is an offence under Section 377 (unnatural offences) of the Indian Penal Code (IPC), the Calcutta High Court recently observed while refusing to quash a criminal case involving charges under Section 377 and allegations of sexual torture of a medical student by his senior. [Dr Raunak Hajari @ Raunak Hajari & Anr v. The State of West Bengal & Anr]