Queen describes Chinese officials as rude

London:  The Queen has been overheard describing Chinese officials as "very rude" while in conversation with a senior police officer at an event celebrating her 90th birthday.

The monarch appeared to make the uncharacteristically unguarded comments during a discussion with a Metropolitan Police Service commander on Tuesday.

It comes hours after British Prime Minister David Cameron was filmed telling her that Afghanistan and Nigeria were "fantastically corrupt".

Queen Elizabeth II speaks with Metropolitan Police Commander Lucy D'Orsi in the garden of Buckingham Palace in London on Tuesday Photo: Pool/AP

The Queen began her conversation with Commander Lucy D'Orsi by quipping "oh, bad luck" when a palace official described how the officer had been assigned to the state visit of Chinese premier Xi Jinping in October.

During the discussion recorded by a BBC cameraman, the official was heard telling the Queen the police had been "seriously undermined by the Chinese" in their handling of the visit, but the officer had managed to "hold her own".

As D'Orsi asked if she knew it had been a "testing time", the Queen interjected: "I did."

Guests attend a garden party at Buckingham Palace in London on Tuesday. Garden parties have been held at the palace since the 1860s. Photo: AP

The officer described how Chinese officials walked out of a meeting with Barbara Woodward, British ambassador to China, at Lancaster House, telling them the trip was off.

The Queen said: "They were very rude to the ambassador."

The remarks were recorded as the Queen greeted guests in the gardens of Buckingham Palace for an event marking her 90th birthday.

Chinese President Xi Jinping, left, toasts with Queen Elizabeth II during a state banquet at Buckingham Palace in London in October. Photo: AP

The Metropolitan Police said it would not comment on the private conversation.

Earlier on Tuesday, Mr Cameron was caught making the unflattering comment about Afghanistan and Nigeria during a conversation with the Queen ahead of an anti-corruption summit, which he is hosting in London on Thursday. Both countries have described the remarks as embarrassing and unfair.

PA