A 27-year-old skydiver has died after plunging into the ground at high speed while attempting a specialist manoeuvre known as swooping.

Tim Fitzsimmons, from Raby, died early this morning after more than 12 hours of surgery at Liverpool Hospital.

He suffered serious internal bleeding along with chest, abdominal and leg injuries following his failed jump at 9.30am yesterday. Paramedics rushed to the Sydney Skydiving Centre at Wilton, in the city's southwest, transporting the experienced BASE jumper and skydiver by helicopter to hospital.

It is believed Mr Fitzsimmons was swooping at the time, a technique where the jumper dives at high speed before using their parachute to pull out of the plunge a short distance above the ground.

"R.I.P big bro. I love you," his sister Nikki Fitzsimmons said on his Facebook page last night.

Police will investigate the death today and will seize the parachute, interview witnesses and examine any video footage of the incident.

Friends last night flooded social media with messages of support for the family of the well-respected skydiver.