Crowner is an official who investigates suspicious death, and so crowner was consulted for Ophelia's burial because her death looked like a self destruction.
Explanation:
Ophelia is one of the character in William Shakespeare's very famous play 'Hamlet.' Ophelia is a wife of Prince Hamlet, and it so happens that due to Hamlet's actions, Ophelia's state of mind is disturbed which resulted in her drowning.
In Act 5 scene 1, two gravediggers enters who argue whether Ophelia should be given a Christian burial. And this mainly because her death doesn't seems like a natural death.
Affter Ophelia's case have been examined by the coroner (crowner), he states that it should be Christian funeral.