Princess Eugenie and her friends were mugged while in Cambodia, according to reports
The incident happened as the Duchess of York's daughter and two gap-year friends were walking at night in Phnom Penh.
When one of her friends got a purse out, the mugger grabbed it. The officers were just feet away.
The two officers rugby-tackled one of the bandits as he tried to flee with the princess's purse.
According to reports, they grappled with the man before another robber started throwing rocks at them. The officers, fearing for the princess's safety, let the thief go, grabbed the purse and led the royal away.
A Buckingham Palace source told The Sun: "They feared the incident was escalating out of control and took the decision to focus on the safety of their principal."
It is the first time in 10 years that SO14 officers have stopped a direct threat to a Royal.
Questions have already been asked over the amount of money spent to keep the princess safe while on the trip. Reports suggest the cost of flights, expenses, accommodation and overtime for the officers will amount to around £100,000 for the six-week stay.
A Buckingham Palace spokesman would not comment on the incident, nor on the princess' security arrangements.