The Queen's grandson founded a charity to oversee the celebrations for the UK monarch's 90th birthday celebrations which then gave the contract for staging the event to his own company, according to Buzzfeed.
Peter Phillips, the son of Princess Anne, devised The Patron's Fund to arrange a mass street party in London for the 600 charities and organisations supported by his grandmother. The charity then contracted his own events firm to make all the arrangements for an undisclosed fee.
Phillips has since stepped down as a trustee of the fund to avoid a conflict of interest, Buzzfeed reports.
The celebrations have already drawn criticism for charging the 10,000 guests to the party £150 (S$302) each.