Meghan Markle and Prince Harry were not paid to take part in the interview, which will air Sunday on CBS

Meghan Markle and Prince Harry's highly-anticipated interview with Oprah Winfrey reportedly cost millions for CBS.

CBS reportedly paid a licensing fee of between $7 and $9 million to air the special, according to The Wall Street Journal. Meghan and Harry were not paid to take part in the interview.

As part of the agreement between CBS and Winfrey's Harpo Productions, the network also obtained rights to license the special abroad. In the United States, the interview is scheduled to air on Sunday, while it will air on ITV in the U.K. on Monday.

For more on Prince Harry and Meghan Markle's interview with Oprah, listen below to the episode of PEOPLE Every Day.

A rep for CBS did not immediately respond to PEOPLE's request for comment.

Prince harry and Megan and Oprah
Prince Harry, Meghan Markle and Oprah Winfrey
| Credit: Joe Pugliese/Harpo Productions

In the latest preview clip from the sit-down, Meghan, 39, revealed that Winfrey previously approached her for an interview ahead of her wedding in 2018 — a request which she turned down.  

"I couldn't have said yes to you then, that wasn't my choice to make," she said, while explaining what makes now the right time to open up.

"We're on the other side of a lot of life experience that's happened and also that we have the ability to make our own choices in a way," she shared. "So as an adult who lived a really independent life to then go into this construct that is different than I think what people imagine it to be, it's really liberating to be able to have the right and the privilege in some ways to be able to say yes. I mean, I'm ready to talk." 

In another preview clip, shared earlier in the week, Meghan addressed how the royal family may feel after hearing her truth.

"I don't know how they could expect that after all of this time, we would still just be silent if there is an active role that the Firm is playing in perpetuating falsehoods about us," Meghan said — "the Firm" referring to the institution of the royal family. "And if that comes with risk of losing things, I mean I — there's a lot that's been lost already." 

Prince Harry, Duke of Sussex and Meghan, Duchess of Sussex
Prince Harry and Meghan Markle
| Credit: Rosa Woods - Pool/Getty Images

On Wednesday, Buckingham Palace announced that it will be launching a probe into bullying allegations against Meghan that were first reported by The Times in the U.K. earlier this week — something her office has strongly refuted.

"The Duchess is saddened by this latest attack on her character, particularly as someone who has been the target of bullying herself and is deeply committed to supporting those who have experienced pain and trauma," a spokesperson for the Duke and Duchess of Sussex said in a statement obtained by PEOPLE. "She is determined to continue her work building compassion around the world and will keep striving to set an example for doing what is right and doing what is good."

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In response to the legal letter to The Times, which reportedly said the newspaper was being "being used by Buckingham Palace to peddle a wholly false narrative" before the Oprah interview, a source told PEOPLE, "It is unfair, untrue and disingenuous to say that the palace is coordinating this."

There "are far more important things we are focusing on," a source adds, referring to Prince Philip's illness and his ongoing care following a heart procedure, the calls that the Queen has been making about vaccinations and the ongoing business of state.

Apart from confirming that they didn't know about the Oprah interview before the news was broken, the palace hasn't commented on what is in the interview.

The CBS interview is expected to cover Meghan's journey from stepping into life as a royal to marriage, motherhood, philanthropic work and facing intense public pressure. Harry will then join his wife to talk about their historic move to the U.S.

Oprah with Meghan and Harry airs Sunday at 8 p.m. on CBS.