Shammi Atwal, 44, died outside Glen & Co. Cash and Carry, his business in Barking, East London, The Daily Telegraph reported. Witnesses told the Metropolitan Police that Atwal was chasing a group of about 10 men who invaded the store.
Police had made no arrests late Tuesday.
"This was a man trying to stop thieves robbing his business. He acted bravely in defense of his wife and managed to chase the robbers from his premises only for him to be pushed in front of a moving lorry," Detective Chief Inspector Neale Baldock, the head of the investigation, said. "People in the community know who committed this appalling and cowardly crime and I would urge them to contact my officers."
Deena Atwal, 37, Atwal's wife, received minor injuries.
Tarsem Singh, 65, called his nephew an "honorable hard working family man."
Singh said Atwal spent most of his spare time at the Sikh temple or engaged in religious charities.
The truck driver stopped after he hit Atwal. He faces no charges.
Kate Middleton recycles dress at movie premiere
Benedict Cumberbatch's dramatic reading of R. Kelly lyrics is just what you need