A man who was found dead in his home on the Coromandel Peninsula may have died "unexpectedly" and "in his sleep", a relative says.

His body was found this morning by police at a Kennedy Bay house after they were alerted to his death by a family member. Police said it appeared he may have died some days ago.

A local resident said the man's death was unexpected.

"It was the unexpected death of a young man.. in his sleep."

Inquiries are underway to determine the circumstances of the man's death.