Police say up to 10 men entered the Glen & Co Cash and Carry in Barking yesterday morning.
Shammi Atwal and his wife - who are co-owners of the business - tried to stop them, causing the gang to flee.
Detective Chief Inspector Neale Baldock said: "This was a man trying to stop thieves robbing his business. He acted bravely in defence of his wife and managed to chase the robbers from his premises only for him to be pushed in front of a moving lorry.
"People in the community know who committed this appalling and cowardly crime and I would urge them to contact my officers."
More top news
Karl Andree, 74, was arrested in Saudi Arabia more than a year ago after the police found 12 bottles of homemade wine in his car.
Sue Gallagher was shocked to read the letter written by a woman who signed her name only as Jodi. The contact details were washed off.
Mike Gapes revealed the bitter splits and turmoil after publicly declaring the party had 'no credible leadership.'