The duchess of Sussex Meghan Markle faced "disgusting" threats to her life from far-right extremists during her time in the royal family, according to the UK's most senior police officer of color.

Neil Basu said in an interview broadcast on Britain's Channel 4 News on Tuesday, that as head of counter-terrorism, he had to deal with credible threats to Markle and her husband Prince Harry that appear to reinforce the couple's claims about security fears.

Meghan, a multiracial former television actor, married the younger son of King Charles III in 2018, but they quit royal life in 2020 amid sustained pressure in the public eye.

Basu, 54, who is retiring after 30 years with London's Metropolitan Police, was asked if there were genuine threats to Markle's life.

"Absolutely," he said, calling the threats "disgusting and very real".

"We had teams investigating it. People have been prosecuted for those threats."

Harry, 38, took the UK government to court to force a review of a decision to pull his state-funded protection when he was back in the country from the U.S., where the couple moved. 

At the beginning of their relationship, Harry publicly criticised the "racial undertones of comment pieces and the outright sexism and racism of social media trolls and web article comments." relating to Markle.

The couple also accused the royal family itself of racism, in a 2021 television interview with Oprah Winfrey.

Basu, whose father was from India, also criticized what he called the "horrific" langauge from senior Conservative politicians of Asian heritage about migrants.

Right-wing Home Secretary Suella Braverman - effectively Basu's boss - has described Albanian asylum seekers as "criminals" and has backed a government scheme to deport failed asylum seekers to Rwanda, a move which campaigners say is illegal.

Basu called the language used "inexplicable" and compared it to an infamous 1968 speech by Conservative MP Enoch Powell warning of a racial war due to immigration.

"It is unbelievable to hear a succession of very powerful politicians who look like this talking in language that my father would have remembered from 1968. It's horrific," he said.

"I was born in 1968. The 'rivers of blood' speech happened in the constituency next to where my parents lived and made their life hell. A mixed-race couple walking through the streets in the 1960s. 

He also acknowledged that his readiness to speak out about racism may have prevented him taking over as the head of the National Crime Agency, to which he was linked.