Coroners investigate deaths if they have reason to suspect that:

When a death is reported to a Coroner they:

The Coroner may decide to hold an Inquest as part of the investigation. 

Other sections on this website explain the different possibilities more fully and the timescales you can expect. In all cases, the Coroner aims to accommodate families' funeral plans while making sure that the investigations are effective and complete.

A guide to the work of the Coroner is available from the Ministry of Justice website.