The video streaming site has allowed several channels to produce videos criticising the Duke and Duchess of Sussex. One account, Murky Meg, has more than 85,000 subscribers and one video carried an advert for human rights charity Amnesty International.
Amnesty International has claimed they advertised through YouTube in a package that applied the company's strictest controls on hateful content.
In a statement, they told Newsweek: "As is common practice, Amnesty International UK advertises on YouTube using their strictest safety settings which should automatically prevent ad placement alongside content that has been classified as hateful or sensational.
"Amnesty campaigns against online abuse and urges social media companies to step up in their efforts to tackle and remove any harmful content."
Another account, HG Tudor, has around 79,600 subscribers and carries adverts from a law firm and a text-to-speech company.
Data analysis agency, Bot Sentinel, identified a network of 83 accounts that were part of a coordinated hate campaign against Meghan.
Referring to the HG Tudor channel, Christopher Bouzy from Bot Sentinel, said: "It's being monetised."
He said: "I would be shocked if the core accounts were not being monetized in some way, whether they're being paid by someone to do this, whether there is some other financial motive behind this.
"I just cannot see these accounts spending so much time each day and there is not something else behind it. Is it just hate driving them?"
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Rashad Robinson, the President of Color of Change, urged for government regulation and enforcement to stop the abuse of women.
He tweeted: "It’s not just Twitter: @YouTube is actively profiting from a coordinated hate campaign against Meghan Markle.
"Without swift government regulation and enforcement, #BigTech will continue to enable the abuse of women and color — and profit."
Express.co.uk has approached YouTube for a comment.
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