The blast in the Hinckley Road shop on 25 February destroyed a supermarket and the flat above where a family lived.
The court was told Mr Hassan was caught on CCTV buying 26.6 litres of unleaded petrol in a drum, which an analyst said matched a drum found at the scene of the explosion.
The court also heard shop worker Viktorija Ijevleva “knew too much” about the plot and was left to die in the fire.
In the flat above the shop, Mary Ragoobar and two of her sons, Shane and Sean Ragoobeer, were killed along with Shane’s girlfriend, Leah Reek.
The third son survived after he was pulled from the rubble. The boys’ father was at work at the time.
Aram Kurd (34), Hawkar Hassan (33) and Arkan Ali (37) deny conspiring to commit fraud and charges of murder and manslaughter.
The prosecution showed jurors CCTV and mobile footage of the explosion in which a loud boom could be heard.
Prosecutor David Herbert QC said “The explosion and fire that followed was deliberately caused by these three defendants as part of a plan to profit from a false insurance claim for loss of stock, contents and future loss of business from the shop that was on the ground floor.”
“The evidence indicates that had the crime been successful the insurance claim would have been in the region of £300,000. It boils down to greed.”
The trial continues.