Derbyshire Police were called to the yard on Tuesday morning where a 24-year-old man from Chaddesden, Derby suffered fatal injuries as a result of the incident involving a road sweeper and a tipper.
He was pronounced dead at the scene.
Derbyshire police are working with the Health and Safety Executive to investigate the circumstances of the incident.
A spokesman for Leedale told the Derby Telegraph: “It was a tragic accident. Everyone is distraught and our thoughts and condolences are with the family at this time.”
Leedale provides a range of construction plant to contractors, developers and local authorities.