A hospital is investigating how a sensitive image of Sydney Harbour shark victim Lauren O’Neill’s horrific injuries was leaked to the public.

The gory image of O’Neill’s mangled leg has been circulating on social media and chat groups.

It reportedly shows a bloodied and gaping wound as the 29-year-old lies on a bed in St Vincent’s Hospital in Sydney.

Discarded blood-soaked bandages can also be seen in the image as a medical staff member holds the patient’s foot and two others watch on.

The graphic image appears to have been taken inside the hospital’s emergency department after O’Neill was rushed there on Monday night.

Doctors performed marathon surgery and managed to save O’Neill’s leg when she was admitted with “severe” injuries.

Hospital spokesman spokesperson David Faktor told Sydney media that the leak of the sensitive photo was under urgent investigation.

“St Vincent’s has become aware of photos in the public domain that appear to have been taken in the Emergency Department and are related to those of a patient injury,” Faktor said on Wednesday night.

“St Vincent’s takes patient privacy obligations extremely seriously and is investigating this issue as a matter of priority.

“We have informed the patient of the photo being taken and circulated online.

“We have sincerely apologised for any part St Vincent’s played in the photos being taken”.

On Wednesday, O’Neill released a statement saying she was expected to make a full recovery, which she credited to the “extraordinary skills” of medical staff.

The avid kayaker and swimmer remains at St Vincent’s Hospital.

She was badly wounded when a shark bit her on the leg while she was swimming near a jetty at Elizabeth Bay, in Sydney’s eastern suburbs, on Monday night.

O’Neill said she was taking a short dip close to the shore when she was mauled by the animal, which authorities believe was a bull shark.

“[Lauren] wishes to thank her heroic and very kind neighbours for the critical assistance they provided her,” a statement issued on her behalf on Wednesday said.

A vet and other neighbours have been praised for their quick-thinking after the attack, including applying tourniquets to O’Neill’s leg to stem the bleeding.

O’Neill thanked her family, friends and colleagues for their unflinching care and support.

“She would also like to thank the public for their outpouring of support and kindness, and as she turns to focusing on her recovery, asks that her privacy and that of her family’s be respected.”

The incident was the first serious attack inside the harbour since 2009, when navy diver Paul de Gelder lost his right leg and hand to a bull shark.

It has prompted debate about the need for more anti-shark measures, including extra netted harbour pools, in order to protect swimmers.

Locals have called for a public enclosed swimming area to be created at Beare Park, near the scene of the attack at Elizabeth Bay.

But plans to build the pool were put on hold by the City of Sydney council last year over water-quality concerns.

Shark nets and smart drumlines are deployed along some ocean beaches, but they are not used at sites within Sydney Harbour.

Shark researchers say there are likely more bull sharks in Sydney Harbour due to warmer water temperatures and the city’s population growing, making encounters with humans more likely.

Sydney University shark policy expert Christopher Pepin-Neff said sharks engaged with their environment mainly by using their teeth, which could lead to them biting unfamiliar creatures.

-with AAP