Melissa Porter, from Perth, Australia, was testing the "swooping" manoeuvre on 24 June when she had a hard landing and fell into shallow water, ABC 13 Houston reported.

Witnesses said her parachute was deployed but she was too close to the ground, according to news.com.au.

Ms Porter, who won gold at the Australian Skydiving Championships earlier this year, was rushed to hospital where she was pronounced dead.

ABC 13 Houston said investigators didn't notice any blunt force trauma to her body and were unsure if she had suffered a medical emergency during the dive.

Ms Porter's mother Vonnie told Australia's 9NEWS: "She's my baby and she's not coming home."

She said her daughter loved the sport.

"That was her happy place. She'll forever be in the sky roaming the world now."

Ms Porter worked as an instructor at Skydive Spaceland Houston.

Swooping involves a series of difficult manoeuvres that allow skydivers to "swoop" at high speeds over the ground or water before levelling off quickly for the landing.

Australia's Department of Foreign Affairs and Trade told the New York Post it was "providing consular assistance to the family of an Australian woman who died in the United States".

"We send our deepest condolences to the woman's family," the department said.

Ms Porter broke an Australian women's total-break sequential record in May when she completed the "2 point 23 way", according to news.com.au.

She told the Sound Telegraph, after winning the Australian championships with her skydiving partner Josh Tassicker: "It was a shock when we took gold but it's been amazing - it definitely makes me want to compete further."