Steve Irwin's family celebrates 'superhero' dad, 20 years after shock death

Australian conservationist Bindi Irwin has marked the 20th anniversary of her famous father's death with a touching tribute to the man best known as the "Crocodile Hunter".

Steve Irwin died on 4 September 2006, aged 44, after a stingray fatally pierced his chest while he was underwater filming a documentary at the Great Barrier Reef.

Bindi, who was eight when her father died, called Steve a "superhero" in an online post on Friday, saying she has "watched the world mourn my dad with our family" for the past two decades.

"I always thought that my dad's legacy is wildlife conservation; it turns out, his legacy is love. For our planet and for each other," Bindi, 28, wrote on Instagram.

She described the impact of her father's death on her mother Terri and her younger brother Robert, 22.

"My mum lost the love of her life; my brother and I lost the greatest dad," she wrote. "Grief never truly leaves us; we walk alongside it every day."

Bindi also shared details on how her daughter connects with the grandfather she never got to meet.

"I have a 5-year-old daughter who watches his documentaries every morning. She feels utterly loved by her 'grandpa crocodile' without ever having met him."