A royal biographer has accused Meghan Markle of using her royal title for monetary gains and claimed she wants to be like Michelle Obama.

Tina Brown, who has written a series of books about Princess Diana, suggested that the 40-year-old is capitalising on her royal connection. She claimed that the Duchess of Sussex has "no purpose" and that Queen Elizabeth II had initially set her up for success.

"She gave her patron of the National Theatre and vice chairman of the commonwealth foundation – no better platform to talk about women's education and the question of minorities," she said during an interview on Washington Post Live about her upcoming book "The Palace Papers: Inside the House of Windsor--the Truth and the Turmoil."

Brown claimed that Meghan Markle is struggling to find a brand after Megxit and relies on social media for ideas. She explained, "Meghan doesn't really have a brand – you feel that she is grasping at the 'Twitter caring' of the moment. Vaccinations, Ukraine, Women's rights, my 40th birthday, let's have a mentoring scheme. Nothing is really going anywhere for Meghan."

Amid the struggles, she and Prince Harry grabbed every opportunity they could get to gain financial independence. She said that the former "Suits" actress "certainly saw the deals that were there to be made because they were royals. It's as though she couldn't resist everything that was on offer on the celebrity buffet."

Brown said that Meghan Markle has "a hunger to avail herself of the global leverage, to live in glorious houses without strings attached." She claimed that the duchess was inspired by the former U.S. First Lady Michelle Obama in her desire to have wealth and stature.

"Meghan gave Harry the tools to leave. She understood the world of agents and deals. I mean this wasn't Harry's world, but suddenly he had in Meghan a very worldly strategist who he decided to trust above all the other advisors," she explained.

Brown claimed that both Prince Harry and Meghan Markle "wanted to be able to have a commercial arm to their activities" after their royal exit. But they "underestimated what it was going to be like to be without the palace platform." They had not realised the importance of the "amazing convening power" of the royals and now they are allegedly struggling to find their own brand and purpose.

Prince Harry and Meghan Markle
Duke and Duchess of Sussex Prince Harry and Meghan Markle Samir Hussein/Wireimage