• Bindi Irwin wrote a heartfelt tribute for her dad, husband and father-in-law on Father's Day
  • She noticeably left out grandfather Bob from her post
  • Irwin claimed she suffered psychological abuse from her grandfather and has to care for her own mental health

Bindi Irwin has made a series of bombshell claims against her estranged grandfather Bob Irwin as she explained why she didn't include him in her Father's Day tribute.

On Sunday, Irwin posted on Facebook a heartfelt tribute for the three most important men in her life — her dad Steve Irwin, husband Chandler Powell and father-in-law Chris Powelll. She also explained how the three "extraordinary men" touched her life in their own ways.

"My dad taught me the importance of strength when standing up for what I believe in and to have empathy for all living beings. My husband amazes me every day with his kind and steadfast heart, his love for our daughter is infinite. My father-in-law works tirelessly for his family and is always there with a word of encouragement," she wrote. "These extraordinary men inspire me and I love them so very much."

However, some wondered why she skipped her grandfather Bob in the tribute. Irwin gave a lengthy explanation in her reply, and it came down to her mental health.

"Unfortunately my grandfather Bob has shown no interest in spending time with me or my family," Irwin claimed in her response. "Publicly he continues to claim that he wants to spend time with us while privately my entire life has been psychological abuse from him."

The "Dancing with the Stars" winner went on to claim that her grandfather has been returning the gifts she’s sent him over the years — after opening them — and ignoring her correspondence.

"From the time I was a little girl he has ignored me, preferring to spend time doing anything else rather than being with me. He has never aid a single kind word to me personally. It breaks my heart but it is not healthy to engage in an abusive relationship," she alleged.

According to Irwin, her mom, Terri Irwin, still writes to her grandfather and sends him birthday and Christmas gifts but has also been ignored by him.

She also claimed that their family has been supporting Bob financially since 1992 after he retired from Australia Zoo. They sent him funds every week, built him a house and ensured his well-being, according to the conservationist.

"I want Bob's happiness in life but I cannot be victim to his mental abuse anymore," Irwin added. "I hope everyone remembers to be kind to one another but most of all care for your own mental health. i have struggled with this relationship my entire life and it brings me enormous pain. I have to choose to care for my own mental health now."

The last time Irwin and her family were photographed with Bob was in 2007, at a memorial for Steve, TMZ noted.

Bindi Irwin
Bindi Irwin, pictured here at the American Humane Association's 5th Annual Hero Dog Awards on Sept. 19, 2015, recently posted a heartfelt message to her late father on International Steve Irwin Day. Getty