Buckingham Palace said on Wednesday that an honorary member of the family has resigned after making «unacceptable and deeply regrettable comments» to a black guest.

«The person in question wishes to express his deep apologies for the damage caused and has stepped down from his honorary position with immediate effect,» the palace said, without naming the person.

Mandu Reid, leader of the British Women’s Equality Party, who witnessed the exchange, identified the person on Thursday as Lady Susan Hussey, 83, godmother to Prince William and lady-in-waiting to the late Queen Elizabeth II.

Ngozi Fulani, director of Sistah Space, a charity that supports victims of domestic abuse, alleged in a tweet that the household member repeatedly pressured her for information about her nationality.

The unidentified Buckingham Palace informant allegedly approached the Fulani at a reception on Tuesday hosted by Camilla, Queen Consort, and asked: «Where do your people come from?»

In a tweet, Fulani said she left her visit to Buckingham Palace with «mixed feelings» and described the encounter in detail.

She said the person approached her 10 minutes after she arrived and «flicked my hair to see my name tag.»

Fulani alleged that the family member peppered her with questions about her nationality and where she had «really come from», even as she explained that she was a British citizen.

In a statement, Buckingham Palace said it took this incident «extremely seriously» adding that it had «immediately investigated to establish all details».

The statement did not identify Hussey.

The palace «communicated with Ngozi Fulani on this matter and is inviting her to discuss all elements of her experience in person if she wishes.» (In a radio interview on Wednesday, Fulani said she had not been contacted.)

«All family members are reminded of the diversity and inclusion policies that they must uphold at all times,» the palace added.

In a tweet on Wednesday, Sistah Space thanked «everyone» for their support and explained that the organization did not want to name the person involved.

«It is the system that needs to be reviewed,» the organization said. «Yes, the person was offensive, but there’s no use naming and shaming them, it would make us just as bad. We’d rather this be handled kindly.»

On Wednesday, Reid tweeted that she saw the encounter take place: «I was there myself. I witnessed this firsthand. We were at an event that was supposed to celebrate our work.

Lady Susan Hussey in Norwich, England on January 19, 2014.
Lady Susan Hussey in Norwich, England, in 2014. File Max Mumby/Indigo/Getty Images

«For people like Lady SH, people like us will never really belong here,» Reid added.

A spokesman for William, the Prince of Wales, denounced the encounter.

«I was very disappointed to hear about the guest experience at Buckingham Palace,» the spokesperson said in an email to NBC News. «Obviously I wasn’t there, but racism has no place in our society.»

«The comments were unacceptable, and it is right that the individual has stepped aside with immediate effect,» the spokesperson added.

The allegations could put a deeper scrutiny on Buckingham Palace, where Meghan, the Duchess of Sussex, last year accused an unidentified whistleblower of racism against her unborn child.

In a televised interview with Oprah Winfrey in March, Meghan and her husband, Prince Harry, said that in the months leading up to the birth of their son, Archie, a royal had expressed «concerns and conversations about how dark their life could be.» skin when it was born».

He did not specify who made the comments because such a disclosure would be «very damaging to them.»

Harry confirmed that he was asked about his son’s skin tone, but did not identify who made the comments or when.

max taylor contributed.