"I have been silent for years and made every effort to keep these matters private," the 26-year-old wrote in a series of posts to his 16 million followers.
"Unfortunately, my parents and their team have continued to go to the press, leaving me with no choice but to speak for myself and tell the truth about only some of the lies that have been printed.
"I do not want to reconcile with my family. I'm not being controlled, I'm standing up for myself for the first time in my life."
He added: "Recently, I have seen with my own eyes the lengths that they'll go through to place countless lies in the media, mostly at the expense of innocent people, to preserve their own facade. But I believe the truth always comes out."
Sir David was photographed on Tuesday morning before taking part in a podcast recording at the World Economic Forum in Davos, Switzerland, but he has so far declined to comment on his eldest son's post.


