A man has died suddenly at a Carterton homekill business this morning.

Emergency services arrived to find the man dead and an animal on the loose at a property on Andersons Line.

Police initially said the animal had been suspended by a crane, fallen and hit the man, but now believe it may have been a medical event.

Further details about the victim and incident are not yet known, and Police are investigating.

Carterton Mayor John Booth said he heard the emergency services sirens screaming past his office this morning.

"Whatever the circumstances are, there'll be a family who will be very, very upset and affected. Our thoughts will go out to the family that is deceased."

WorkSafe has been notified of the incident and is making initial inquiries.