Britain's Queen Elizabeth II on Tuesday responded to explosive racism claims from her grandson Prince Harry and his wife Meghan, voicing deep concern and sympathising with their troubles with royal life.

"The whole family is saddened to learn the full extent of how challenging the last few years have been for Harry and Meghan," she said in a statement.

"The issues raised, particularly that of race, are concerning. While some recollections may vary, they are taken very seriously and will be addressed by the family privately.

Since leaving Britain, Prince Harry and his wife Meghan have settled in Montecito, an affluent community 90 minutes up the coast from Los Angeles
Since leaving Britain, Prince Harry and his wife Meghan have settled in Montecito, an affluent community 90 minutes up the coast from Los Angeles AFP / Ben STANSALL

"Harry, Meghan and Archie will always be much-loved family members."

Buckingham Palace has come under mounting pressure to respond to the claims made in an Oprah Winfrey interview first broadcast on Sunday, which triggered a crisis unseen since the anguished days of Harry's late mother, Diana, in the 1990s.

It set off a whirl of speculation about the identity of the senior royal who asked how dark their child's skin would be before he was born.

The Wall Street Journal reports that Oprah sold the interview with Harry and Meghan to CBS for $7 to $9 million
The Wall Street Journal reports that Oprah sold the interview with Harry and Meghan to CBS for $7 to $9 million AFP / NICHOLAS KAMM

Meghan, whose mother is black and father is white, also spoke about how she had suicidal thoughts, but failed to receive any support during her time in the royal family.

Winfrey was left open-mouthed by the racism claim, which reportedly left the palace in turmoil and scrambling how best to address it.

Prince Charles, Harry's father and the heir to the throne, earlier ignored a question about what he made of the interview, as he made his first public appearance since the row erupted.

A YouGov poll of 4,656 people after the interview aired on British television on Monday indicated almost a third (32 percent) felt the couple was unfairly treated, the same proportion as those who thought the opposite.

Meghan has accused Buckingham Palace of "perpetuating falsehoods about us"
Meghan has accused Buckingham Palace of "perpetuating falsehoods about us" POOL / John Stillwell

But older people were more likely to side with the royal family, the poll suggested.

Prince Harry and Meghan Markle spoke out in an interview with Oprah Winfrey that immediately became one of the most extraordinary chapters in recent royal history
Prince Harry and Meghan Markle spoke out in an interview with Oprah Winfrey that immediately became one of the most extraordinary chapters in recent royal history AFP / OLIVIER DOULIERY

Harry and Meghan's claims have been likened to a bomb being dropped on Britain's most famous family and one of the country's most revered institutions.

Attempts have been made to draw in Prime Minister Boris Johnson, who has himself been accused of racism during his time as a newspaper columnist.

But he refused to comment, even as political calls mounted for a full inquiry and the White House and former US secretary of state Hillary Clinton spoke out.

However Zac Goldsmith, a junior British foreign minister and close ally of Johnson, said former army captain Harry was "blowing up his family".

Prince Harry's wife Meghan Markle speaks of her suicidal thoughts during her tell-all interview with Oprah Winfrey
Prince Harry's wife Meghan Markle speaks of her suicidal thoughts during her tell-all interview with Oprah Winfrey CBS / Sébastien VUAGNAT

Johnson's spokesman declined to say whether Goldsmith was speaking for the government.

The level of controversy about the royals has not been seen since the 1990s, during the very public collapse of the marriage of Harry's parents.

His mother, princess Diana, collaborated with the author Andrew Morton in a revealing 1992 biography and gave a bombshell BBC television interview in 1995.

In it, she said both she and Prince Charles had been unfaithful, how he was unfit to be king, and that she felt isolated, struggling with self-harm and bulimia.

Morton said Harry and Meghan's claims would "shudder down through the generations in the same way that Diana's did".

But Meghan's estranged father Thomas Markle defended the royals, saying he hoped the skin tone comment was "just a dumb question".

"It could just be that simple, it could be somebody asked a stupid question, rather than being a total racist," he told Britain's ITV.

Just over 17 million viewers watched Winfrey's two-hour interview with Harry and Meghan on US broadcaster CBS on Sunday night.

More than 11 million people then tuned in to watch it in full on ITV in Britain, the channel said.

The couple dramatically quit royal life last year and now live in California with their young son, Archie, and are expecting their second child, a daughter, this summer.

Harry, 36, has admitted his mother's death in Paris in 1997 -- in a high-speed car crash as she tried to flee paparazzi photographers -- has affected his mental health and coloured his view of the media.

He and Meghan, 39, have accused newspapers of racial stereotyping, particularly set against coverage of Harry's sister-in-law, Kate, who is white.

But their comments about the suffocating strictures of royal life and claims of unwavering attitudes have wider implications for the monarchy itself -- and what it represents.

Black Lives Matter protests last year prompted calls for a reassessment of the legacy of the British Empire headed by the queen and her ancestors.

Neither the queen, now 94, and her 99-year-old husband, Prince Philip, made the racist comment, Winfrey told CBS.

But it could still be damaging as the monarch is head of the Commonwealth, an organisation comprising 54 mainly former British colonies, many of them in Africa, and 2.4 billion people.

Mass immigration has transformed Britain since the queen came to the throne in 1952, with a rising number of people who define themselves as British-Asian, black-British or of mixed race.

The historian David Olusoga wrote in The Guardian that Harry and Meghan's claims were "not just a crisis for the royal family -- but for Britain itself".

But he has said meeting Meghan had made him confront the issue, and he is now championing projects to tackle racism.