The Prince and Princess of Wales’ first overseas trip since the Queen’s death has been overshadowed by controversy at home.

William and Kate arrived in Boston yesterday for a three-day visit before the Earthshot Prize, the prince’s environmental awards ceremony, on Friday.

Hours earlier, the prince’s godmother resigned from her duties at Buckingham Palace after repeatedly asking a black visitor “where she really came from”.

A Kensington Palace spokesman who spoke to William before he boarded his flight said Lady Susan Hussey’s comments were “unacceptable” and that “racism has no place in our society”.

He added that Lady Hussey, 83, was right to have stepped aside from her honorary role as Lady of the Household with immediate effect.

The monarchy has faced allegations of institutional racism since Ngozi Fulani, a British-born charity boss, revealed what had happened at an event in Buckingham Palace on Tuesday.

Lady Hussey, who served as the Queen’s lady in waiting for more than 60 years, has offered her “profound apologies for the hurt caused”.

William focused on the Earthshot Prize as he greeted crowds in Boston, saying: “We are both looking forward to spending the next few days learning about the innovative ways the people of Massachusetts are tackling climate change.”

The White House has confirmed that the royal couple are set to meet Joe Biden, the president, later this week.

William and Kate sat courtside to watch an NBA game and were booed by small pockets of the crowd around the stadium when they were introduced by an announcer and shown on the big screen.

At one point, some fans in the crowd could be heard loudly cheering “USA, USA” when the couple appeared on the screens in the centre above the court.

Charity boss reacts to resignation

Buckingham Palace said yesterday that it was taking the incident “extremely seriously” and described Lady Hussey’s comments as “unacceptable and deeply regrettable”.

Ms Fulani works as an advocate for survivors of domestic abuse and described the exchange as a “violation”.

Speaking to LBC, the chief executive of Sistah Space said “nobody from the palace has spoken to me”, but she would be “happy to have a conversation to bring about a positive solution”.

Reflecting further, she said: “To be honest I wish that the lady could be spoken to and know the damage she has caused and preferably not be front-facing.

“But for her to resign, that has nothing to do with me. I don’t feel good about that. She’s an elder and in my culture we respect elders.

“Conversations need to be had with the relevant people so this kind of thing doesn’t happen again.”

Last year, the Duchess of Sussex claimed that a member of the royal household raised concerns about what colour skin her son Archie would have before he was born.

Royals must ‘step up’

Mandu Reid, leader of the Women’s Equality Party, who was standing next to Ms Fulani and witnessed the exchange, said she was “stunned”.

“It was really uncomfortable. If Ngozi was a white woman there is no way that line of questioning would have taken place. It’s not what you expect,” she told Sky News.

“We weren’t gate crashers, but we were made to feel almost like trespassers.”

Asked if she was reassured by Lady Hussey stepping down and apologising, she said no – and that the royals need to “step up” and acknowledge that “institutional racism is part of the culture”.