SYDNEY – “Crocodile Hunter” Steve Irwin, the quirky Australian naturalist who won worldwide acclaim, died today in a marine accident, apparently killed by a poisonous stingray barb that pierced his chest, Australian media reported.

Irwin, 44, was filming an underwater documentary on the Great Barrier Reef off northeastern Queensland state when the accident occurred, The Daily Telegraph newspaper in Sydney reported on its Web site.

Irwin, whose television show “The Crocodile Hunter” won international acclaim and popularized the exclamation “crikey,” was believed to have been killed by a razor-sharp barb that pierced his chest, the Herald Sun newspaper said.

Sky Television reported that Irwin had been stung by a stingray.

The Australian Broadcasting Corp. said Irwin was diving off Low Isles near the resort town of Port Douglas, about 1,260 miles north of Brisbane.

A helicopter carrying paramedics flew to the island, but they were unable to save him, ABC reported on its Web site.

Stingrays are the largest of the venomous fish, and their tails carry at least one sharp barb or spine. The barbs are covered by a film of venom and mucus.

Irwin, a father of two, won a global following for his daredevil antics, but also triggered outrage in January 2004 when he held his then 1-month-old son while feeding a snapping crocodile at his Australian zoo. He had tucked the infant under one arm while he tossed the 13-foot reptile a piece of meat with the other.

Authorities declined to charge Irwin for violating safety regulations.

Later that year, he was accused of getting too close to penguins, a seal and humpback whales in Antarctica while making a documentary. Irwin denied any wrongdoing, and an Australian Environment Department investigation recommended no action be taken against him.

“The Crocodile Hunter” was first broadcast in Australia in 1992 and has aired in the U.S. and around the world on the Discovery channel.

Irwin rode his image into a feature film, and developed the Australia Zoo as a tourist attraction.

Irwin’s American-born wife, Terri, was trekking on Cradle Mountain in Tasmania, the Herald Sun said, and efforts were underway to inform her of her husband’s death.