Crocodile Hunter's son, 4, wants TV show

Bon Irwin, son of the late Steve Irwin, may only be four years old, but already duty calls. He is determined to follow in the footsteps of his "Crocodile Hunter" father and present his own wildlife television show.

Bob's ambitions were disclosed by his mother, Terri, during a television interview aired last night. Bob's big sister, 10-year-old Bindi, has already achieved international stardom, having made a 26-part TV series for the Discovery Channel. But Mrs Irwin firmly rejects suggestions that the children are being exploited, or denied a normal childhood.

She revealed to Australia's Channel Nine that the family have a daily ritual: every morning they watch a DVD of Mr Irwin, who was killed by a stingray's barb at the Great Barrier Reef two years ago.

"It's nice while we're having breakfast to hear Steve's voice in the background," Mrs Irwin explained. "It's special."

Channel Nine's 60 Minutes programme filmed the Irwins on a trip to their wildlife reserve in Cape York, in far north Queensland. Bob, whom his mother calls "a little Steve clone", is seen cradling reptiles and clambering on the back of a 10-foot crocodile. Bob is even shown filming a little segment about owls, facing down the camera and chatting with his audience, in his father's style. With his mop of flicked blond hair, cheeky smile and miniature khaki safari suit, he closely resembles Mr Irwin. And he has more than a touch of his trademark ebullience.

Both children have minds of their own, according to their mother. At Cape York, Bob is seen climbing a tree. Bindi offers to help him. He declines, declaring: "I'm Mr Independence."

Mr Irwin, host of the TV show, Crocodile Hunter, was famous for his close-up antics with dangerous wildlife. He was bitterly criticised for feeding a snapping croc at the family's Queensland wildlife park, Australia Zoo, while cradling Bob, then just one month old, in his arms. If psychological damage was done, it does not show. Bob is fearless, and appears in his element in the wilderness. "You did a great job," he tells his mother after she helps some crocodile handlers release a man-eating saltwater specimen.

After Mr Irwin's death, the Australian government gave his widow a $6.4m (£2.9m) grant to buy up 135,000 acres of land on Cape York, since named the Steve Irwin Wildlife Reserve. Last week, she lost a legal battle to prevent a bauxite mining company carrying out exploration work on the land.

Mrs Irwin, who was born in America, has weathered one controversy after another. She has been heavily criticised over her daughter's commercial activities, which have included producing a children's fitness tape, her own clothing range and a Bindi action doll.

Meanwhile, the Australian Taxation Office is investigating Mrs Irwin's involvement in an offshore tax minimisation scheme. There have been persistent rumours of an affair with Mr Irwin's close friend and colleague, John Stainton, which the latter has vehemently denied.

Most damagingly, Mrs Irwin has been engaged in a public split with her father-in-law, Bob, who walked out of Australia Zoo, which he founded 36 years ago, amid rumours that he believed she was over- commercialising the already hugely profitable venture. One Australian newspaper noted yesterday that, rather than Little Bob, Mrs Irwin now calls her son Robert.

Earlier this year, she proudly told the world that Bob, or rather Robert, had "copped his first hit", after being bitten on the finger by a baby boa constrictor.