Bindi Irwin shares touching tribute to her dad on what would have been his 58th birthday

Sunday would've been beloved Australian wildlife expert Steve Irwin's - aka "The Crocodile Hunter" - 58th birthday.

To mark the emotional occasion Bindi Irwin took to Instagram with a heartfelt post in honour of her late dad - who died in September 2006 - by sharing a never-before-seen photo of the two of them together.

Alongside the photo, she wrote: "Dad, Today is your birthday. I had an extra-strong cup of tea just how you liked it. I hugged Mum for you and told her how much we love her.

"Robert and I went on a hike through the mountains you cherished. I watched one of your documentaries with Chandler and shared stories about you. I walked through your office in the zoo and smiled at our old family photographs.

"Today and every day I miss you and love you beyond description. You’re always with me."

The 21-year-old beauty lost her fearless dad when she was just eight years old. 

Steve's son Robert also shared a tribute of his own.

Sharing a black and white family portrait from when Steve was alive, Robert simply wrote: "Family Always."

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Family Always ❤️ . . . 📷: Tim Bauer

A post shared by Robert Irwin (@robertirwinphotography) on

Bindi's fiance Chandler Powell also shared his own post, thanking the Australian for "inspiring" him.

"Thank you for inspiring me and the whole world to love all wildlife," Chandler wrote alongside a photo of Steve. "You would be so proud of Bindi, Terri and Robert carrying on the amazing work you started.

"We will all make sure your message lives on for generations."