But he has no doubts about the ceramics in the collection of the late Sydney judge Roddy Meagher bequeathed to the university in 2009: ''Some of them are fakes and even not good grade fakes''.

Most Australian householders buying ''made in China'' plates are only dimly if at all aware that they are partaking in a trade going back 1200 years when China began shipping mass-produced stoneware and porcelain to south-east Asia and the Persian Gulf.

The marvel that 1000-year-old porcelain can look as fresh as the day it was made, even after sitting on the ocean floor for hundreds of years, was one of the things that attracted 38-year-old Dr Li to its study.

That, and the prospect of sleuthing around shipwrecks.

''It is like a detective story,'' he says gleefully. It fascinates him such goods are so closely identified with his motherland that Westerners call them ''china''.

In the bowels of the Fisher Library at Sydney University, Dr Li selects a small green jar from a shelf of plates, wine bottles, bowls, tea cups, vases and cat figures from the Meagher collection.

''I think we are very lucky today. He is waiting for us. It is really like seeing an old friend,'' he says of the jar, cradling it in gloved hands.

It is celadon, moulded dragon design, from the Longquan kilns in Zhejiang province, around 14th century, he declares. The type, mass produced for everyday use, is often found in shipwrecks or at land sites in south-east Asia.

On the base is a sticker from the David Jones Gallery, where Meagher often bought things. Dr Li guesses the jar's value at around $10,000. Fakes are the exception in the collection, he says. ''The large part is OK.''

The university's museums and cultural engagement director, David Ellis, is unfazed. He says there is much work still to be done to tie down the provenance of the Meagher pieces.

Meagher was a ''particularly erudite'' collector who ''really knew his history'' and applied his own aesthetic sense to his purchases, as private collectors do. ''He might have been attracted to a 20th century copy, but it was a beautiful 20th century copy,'' says Mr Ellis.

The so-called Belitung wreck of a ninth century Arab dhow discovered in Indonesian waters in 1998, yielded some 60,000 intact pieces including a bowl with a date inscription corresponding to 826 AD.

But the facts rarely present themselves so clearly. Using what he calls ''chemical fingerprinting'' to identify the source of the raw materials, Dr Li and colleagues have traced some of the Belitung pieces back to ancient kilns in Henan province. Their academic work relies on an ''holistic approach that integrates different disciplines of archaeology, art history, historiography and chemistry'' to get behind that ageless quality.

And when he holds an item in his hands? ''You use all your senses. It is often the first impression - gut feeling,'' he says.

Dr Li Baoping, left, speaks at Sydney Ideas at the Sydney University Law School foyer on Tuesday February 12, 6-7.30pm.