Basu said there had been threats to Ms Markle's more than once, adding: “We had teams investigating it. People have been prosecuted for those threats.”
Former counter-terror chief Neil Basu said the police investigated ‘many’ credible threats against Prince Harry’s wife, Meghan Markle while she was living in Britain.
Basu, who is stepping down as the Met’s Assistant Commissioner of Specialist Operations, in an interview on Tuesday said the threats against the Duchess of Sussex were 'disgusting' and 'very real', Daily Mail reports.
Asked if they were credible, he replied: “Absolutely, and if you'd seen the stuff that was written and you were receiving it… the kind of rhetoric that's online, if you don't know what I know, you would feel under threat all of the time.”
Mr Basu said there had been threats to Ms Markle's more than once, adding: “We had teams investigating it. People have been prosecuted for those threats.”
In a searing interview as he prepares to leave the Met after 30 years, he also suggested his outspoken views on race had seen him blocked from becoming head of the National Crime Agency and demanded a crackdown on racist officers.
Basu, who was Britain's most senior ethnic minority police officer, told Channel 4's Cathy Newman about his personal experience of racism and said his outspoken views on the issue saw him lock horns with the government.
He claimed this may have cost him the chance of taking over as head of the National Crime Agency.
The former top cop suggested racism was still a problem in the police and said new Metropolitan Police Commissioner Sir Mark Rowley was “doing the right thing” by calling for more powers to sack officers.
Basu said he was proud to be woke, telling Ms Newman: “Are you alert to issues of racial and social justice? Yes, I am.
“And if that is the definition of woke, I'll wear it as a bumper sticker every day of the week.
“And by the way, every serving police officer, let alone a Chief Constable, better believe that too.
“We serve all of the public without fear or favour, regardless of who they look like, not just the people we like.”
Mr Basu also hit out at Home Secretary Suella Braverman for her comments about how it was her 'dream' to send migrants to Rwanda.
“I find some of the commentary coming out of the Home Office inexplicable,” he said.
“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 the 1968. It's horrific.
“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. Stoned.”
He added: “I speak about race because I know something about race because I'm a 54-year-old mixed race man.”
The Home Office said in a statement: “The Home Secretary expects forces to take a zero-tolerance approach to racism within their workplace.
“But she is also very clear about the need to manage our borders effectively and have an asylum system that works for those in genuine need, as are the British people.
“We are actively pushing for a cultural change in the police, including via a targeted review of police dismissals to ensure officers who are not fit to serve can be swiftly removed.
“There ought to be a zero tolerance for people who are prejudiced, who are corrupt, who are – have the kind of backgrounds of the ones you've described that shouldn't be anywhere near policing.”