Why did Goa Police register Nana Patekar's death as 'unnatural'?

Legendary actor Nana Patekar's death has been registered as "unnatural" by Goa Police as a standard protocol because he was brought dead to the hospital. The term "unnatural death" in a police record does not by itself mean that foul play is suspected. Police has registered the case to conduct an inquest into the circumstances surrounding Patekar's death.