Kim was attending the Hollywood launch of her perfume on Thursday (March 22), when an unidentified woman dumped a bag of flour over her head. The reality star was allegedly targeted because she has worn fur in public.
PETA has since denied responsibility for organising the altercation, but expressed willingness to help fund the attacker's defence.
Kim's sibling Khloe previously posed for PETA's 'I'd Rather Go Naked Than Wear Fur' campaign, but she has now renounced her support for the group.
"I've been a vocal supporter of PETA for a long time but I have also been very vocal about anti-bullying, so this was a huge disappointment for me," Khloe blogged. "As you all know, I don't condone violence and bullying and what happened last Thursday was just that. I am absolutely disgusted by their behaviour."
She went on to write: "Everyone is entitled to their own beliefs and opinions - I personally don't wear fur but that doesn't mean I am going to force my views on anyone else, ESPECIALLY by violating them.
"I am a very proud sister right now, because Kim handled last week's incident like a champ. She got cleaned up and was back out there in a matter of minutes. Go Kimmie!"
Khloe closed her blog by promising to continue supporting animal rights without directly backing PETA.
"We all need to practice what we preach. I will still continue to NOT wear fur, but I will no longer support PETA. Bullying and harassment is NEVER a solution, and I won't be a part of any organisation that thinks otherwise," she vowed.
Kim reportedly chose to press charges against the attacker in order to encourage people not to use violence to get their political messages across.