The torso and replica head of the statue of a goddess, dating back to the reign of Tutankhamun in 1300 BC, were ceremonially joined in a Sydney University gallery.

The torso has been at the University's Nicholson Museum since 1860 and very little was known about it until two years ago, when a scholar, using photographs, made a match with the head at the Egyptian Museum in Cairo.

American academic Ray Johnson, an expert in statuary of the period, wrote to the two museums and suggested they measure their respective pieces for a possible fit.

Some of the best discoveries are made in museums

Egyptian Museum Director-General Mohamed Saleh brought a cast of the head to the Nicholson Museum and will take back a cast of the torso, so both museums can display their pieces in a complete form.

Mr Saleh said although archaeology was the business of unearthing the past, the swap demonstrated that many great discoveries were made in museums.

Archaeologists were unable to transplant the original head as Egyptian law prevents Tutankhamun artefacts from being taken out of the country.

The beautifully-carved statue in lustrous black volcanic rock at Sydney University is believed to depict either Isis or Hathor, both important Egyptian goddesses.

Its head has rested in the Egyptian Museum in Cairo since late last century after being found in the Temple of Karnak in modern Luxor.

The torso was taken to Australia in the late 1850s and donated to Sydney University in 1860 by Charles Nicholson, a respected scholar and collector after the gallery is named.