Robert Irwin fights back tears as he remembers late father Steve in his most emotional interview yet

Robert Irwin fought back tears this week in an emotional interview with Anderson Cooper.

The Wildlife Warrior, 21, was chatting to the US broadcasting veteran on his podcast All There Is about how he processes grief in the wake of his father, Steve Irwin's death.

Steve 'The Crocodile Hunter' Irwin died aged 44 off the coast of Queensland in 2006, after being pierced in the chest by a stingray while filming a nature documentary.

During the expansive interview, Robert became visibly emotional when Anderson asked if he still communicated with his father.

'Yeah, there are... there are moments where...' Robert began before choking up.

Anderson replied: 'If it's too personal, it's fine.'

Pushing on, Robert revealed that he feels closest to his father when he is by himself in nature.    

'There are moments where... I'll sit... I'm always closest to Dad when I'm in the middle of nowhere, you know, when I'm out in the bush,' he said.

'There are absolutely moments where I'll be hit with this sense of... it's warmth – it's like something kind of wraps around me.'

He then revealed the heartbreaking question that he asks Steve in those private moments.

'I will absolutely sit and just say: "How do I, like, how do I go forward", you know? How do you move forward? 

Continuing, Robert said that while he is constantly reminded of his father, those moments alone provide the biggest catharsis. 

'[With] my dad always being this constant thread in my life and people always talking about him, sometimes one of the nicest things is to just sit... in nature and I just kind of let it all go,' he said.

'I let it all sort of pour out and it feels like I'm kind of letting him in. Sometimes I sit and just go: "What's next? How do I put one foot in front of the other?" And there's no answer, but it almost feels like there's a resolution that comes out of that.'

While Robert admitted that his father's presence was palpable, his absence was still felt just as deeply.

'Growing up, it was comforting the fact that I had his presence around, that I could see him in videos and pictures,' he said.

'When I walk around our place here at Australia Zoo, when I'm in the place that he built... I feel him so completely, but it's impossible not to feel that equal sense of emptiness from him not being here.'

Robert also became emotional when he revealed that his biggest fear, still, was forgetting how his father 'felt,' while adding that his mother Terri was instrumental in keeping Steve's memory alive. 

'For me growing up, my greatest fear – and it still is my greatest fear – is forgetting what he feels like or what he felt like,' he said. 

'And that was something that would for a long time really, really keep me up at night. But I think one of the greatest saving graces in keeping him alive in my life is my mum.  She is the reason why I have such a clear picture of the person that he was.'

It comes after Robert became emotional while chatting about his late father in June last year.  

Appearing on BBC Radio 2's Scott Mills Breakfast Show, Robert, 21, was played a clip of Steve that showed him outlining his dreams for him and his sister, Bindi, 26.

Steve's voice began to crack with emotion as he admitted that seeing Robert and Bindi take up the Wildlife Warrior mantle would be his 'proudest moment'.

Visibly moved by his father's words, Robert admitted that his dad would always be his 'superhero'.

'It's emotional to hear that,' he said. 'He is my superhero – he always will be. And he was, I think, a superhero to an entire generation.'

Steve died on September 4, 2006, after being pierced in the chest by a short-tail stingray barb while filming in the Great Barrier Reef with Philippe Cousteau Jr.

A private funeral service was held on September 9, and Steve was buried in a private ceremony at Australia Zoo later that same day.

A public memorial service was held in Australia Zoo's 5,500-seat Crocoseum on September 30, and was broadcast live to an estimated audience of more than 300 million.