The British Council has pledged to investigate comments, allegedly made by one its senior employees on Facebook, which criticise Prince George for living "on public money".
Angela Gibbins, head of global estates at the charity, was reported to have commented on a picture of the young Prince which someone had captioned: "I know he's only two years old, but Prince George already looks like a f****** d***head."
The British Council, which promotes the UK and the English language in more than 100 countries, said her alleged comments, in which she called Prince George "royal, rich" and "advantaged" and referenced "white privilege", were not representative of the organisation's views.
A spokeswoman said: "This comment was made on a private social media account.
"It has absolutely no connection to the British Council and does not represent the views of the British Council.
"That said, we expect the highest standards of our staff and we will be investigating the matter further."
Ms Gibbins' apparent comments, which were reported in The Sun, were on a photograph of Prince George - who has just turned three - taken for a set of stamps to celebrate the Queen's 90th birthday when he was two years old.
She allegedly said: "White privilege. That cheeky grin is the innate knowledge he's royal, rich, advantaged and will never know *any* difficulties or hardships in life.
"Let's find photos of 3yo Syrian refugee children and see if they look alike, eh?"
When she was criticised by other Facebook users, Ms Gibbins is said to have responded: "I'm sound in my socialist, atheist and republican opinions.
"I don't believe the royal family have any place in a modern democracy, least of all when they live on public money. That's privilege and it needs to end."
The British Council has a Royal Charter and its patron is the Queen.
Earlier this month, Prince George's parents the Duke and Duchess of Cambridge met schoolchildren in France who were taking part in British Council programme.