Thomas Henderson, 63, former head of ShelterBox UK, used his position as CEO to hand supply deals to his son John, 34, making 'significant' gains, it is alleged.
The charity, which was founded in Henderson's garage in Helston, Cornwall, in 2000, grew to be a major international relief agency and counts the Duchess of Cornwall as a patron.
It grew 'exponentially' after its foundation, notably giving aid in the 2004 Boxing Day Tsunami and 2010 Haiti earthquake.
But the Old Bailey heard today that for five years its boss, with the help of employee Darren Gervis, 41, rigged its supply chain for the benefit of his son.
The court was also told that John Henderson 'inflated' invoices so he could buy a house.