A human leg bone discovered in Sydney Harbour is being carbon tested to determine its age and whether it could be from a nineteenth century shipwreck.
The leg bone was discovered by scuba diver John Swift at Middle Head in May 2011.
Testing conducted in September that year found the femur belonged to a caucasian male aged around 18 but it is still unclear how old the bone is.
It was found less than 30m from the site of the Edward Lombe shipwreck in which 12 men perished in 1834.
Tests are now being conducted to determine whether the bone is older than 100 years, after an inquiry into it at Glebe Coroners Court was adjourned on Friday.
Counsel assisting the coroner Deb Williamson told AAP the bone would undergo a test known as bomb pulse dating, which determines whether the bone post-dates the episode of nuclear weapons testing after World War II.
But she said there's no possibility the bone belonged to one of the Edward Lombe crewmen, because bodies were recovered at the time.
"The heritage office is of the view that there's no way the bone could have been as a result of the loss of the vessel in 1834," she said.
Following the carbon testing, which will take at least three months, the bone will also be tested against the DNA of family members who have reported missing persons.
An inquest into the bone will resume for mention on January 11.
© AAP 2017