"I can't tell you how frustrating that is", Clooney said.
The tone of the coverage on Meghan has shifted in recent months, amid reports that the duchess has been upsetting the royal staff and whether she has fallen out with Kate. "The impact it was having on her that we would then see and feel was very hard to understand", William said in the documentary.
Clooney is a friend of Meghan's and he and his wife, Amal Clooney, attended Meghan and Prince Harry's wedding a year ago. But she's eight months pregnant, and vilified and persecuted her as Diana.
Clooney said it was "irresponsible" and that Meghan was getting a "raw deal".
It's been a tough few days for Meghan after her father Thomas Markle shared extracts from a heartbreaking five-page letter - which was allegedly written by the Duchess of Sussex herself - with the Mail on Sunday, showing the depths of his daughter's grief over their estrangement.More news: Eden Hazard relishing Chelsea partnership with Gonzalo Higuain
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In neat handwriting, she accused him of breaking her heart "into a million pieces" by giving interviews to the media, making up stories and attacking Harry.
They also claimed Thomas had "never called, never texted", saying this has been "super painful" for the soon-to-be mother.
"We worry about what this is doing to her and the baby", she continued. He knows how to get in touch with her.
Last month, five of Meghan's close friends told People magazine the duchess had endured "lies and untruths" and "global bullying" and they anxious how this would affect her and her baby.
"Dad, I'm so heartbroken, I love you", the letter reads.
"While the goal of Meghan's letter was very much to fix the relationship with her father, she knew in her heart of hearts that this was going to be released to the papers", he said.