Bindi Irwin has hailed her late father Steve Irwin as her "hero".

Bindi Irwin and Steve Irwin

Bindi Irwin and Steve Irwin

The 18-year-old actress took to Twitter on Saturday (03.09.16) to mark the 10-year anniversary of her father's death.

The wildlife expert died in 2006 aged 44 after he was attacked by a stingray that pierced his heart, causing him to bleed to death, while filming the documentary series 'Ocean's Deadliest'.

On Twitter, Bindi - who is also a wildlife conservationist - said: "You'll be my hero for my entire existence. I love you more than words can describe."

The tweet was followed by a picture of her late father holding her as a baby in a heartfelt celebration to his legacy.

At the same time, the winner of 2015's 'Dancing with the Stars' also tweeted a philosophical quote from the Dalai Lama.

She tweeted: "Happiness is not something ready made. It comes from your own actions. - Dalai Lama (sic)"

The gesture comes just days after a letter from the late TV star was found by his father in the jacket of a book.

The letter was addressed to both of Steve's parents Lyn and Bob, in which the former star of 'The Crocodile Hunter' said his parents were his "best friends".

The letter read: "Probably one of the most unfortunate things in a 'bloke's life' is that it takes over 30 years to realise how essential you have been to build my character, my ethics and, most importantly, my HAPPINESS.

"At 32, I am finally starting to figure it out. In good times and in bad, you were there. Your strength and endurance to raise me will not go unrewarded. My love for you is my strength!

"For the rest of my life I will reflect on the unbelievably GREAT times we've shared and will continue to share. You're my best friends! (sic)"

The full letter will be published in a memoir, entitled 'The Last Crocodile Hunter: A Father and Son Legacy', that will be released later this year to commemorate a decade since his passing.