Meghan Markle's half brother Thomas has claimed the Duchess brutally "dumped" her first husband before she married Prince Harry.
The baseless speculation was included in a clip from an upcoming reality show set in Australia.
In a new preview for the upcoming Channel 7 series Big Brother VIP, Thomas Markle Jr. continued his tirade against his royal sibling, with whom he shares a father, Thomas Markle.
The 55-year-old, who Meghan has previously claimed she has had nothing to do with, is a contestant on the upcoming all-star reality series.
In a new preview, Thomas is heard telling his fellow cast mates that Meghan "walked all over" her first husband, US producer Trevor Engelson.
"The guy she was married to the first time … She just walked all over him and dumped him," Thomas is heard saying.
"Harry's on the chopping block next."
Thomas is then seen sitting in the diary room, declaring he will "write a letter" to Harry and Meghan on camera.
"Dear Meghan and Harry, the first thing I want to say to both of you is …".
It comes after a first teaser was released in August, in which Thomas said: "I told Prince Harry, I think she's going to ruin your life. She's very shallow."
Big Brother VIP is expected to premiere in November.
Caitlyn Jenner, former MAFS star Jessika Power and Donald Trump's former political aide Omarosa are among the celebrities set to star.
Engelson, 44, began dating a then-budding actress Meghan in 2004. They were married in Jamaica in 2011 before divorcing 18 months later citing "irreconcilable differences".
Meghan, who was starring on the TV series Suits, met Prince Harry on a blind date in mid-2016, before they became engaged in October 2017.
They were married in May 2018 at Windsor Castle and have since had two children, Archie, 2, and Lilibet Diana, who was born in June this year.
Addressing her relationship with her outspoken siblings – specifically her half-sister Samantha Markle – Meghan told Oprah Winfrey in March that she didn't "feel comfortable talking about people that I don't really know", in response to claims Samantha was writing a tell-all book.
She also revealed she no longer has a relationship with her father, Thomas Markle.
"I think it would be very hard to tell all when you don't know me. I mean, this is a very different situation than my dad, right? When you talk about betrayal, betrayal comes from someone that you have a relationship with," Meghan told Oprah.
"She changed her last name back to Markle in – I think she was in her early fifties at that time – only when I started dating Harry, so I think that says enough."