Police are reviewing security camera footage in their investigation of the theft of more than 500 jewels from a trade fair in Sydney.
Officers believe the uncut diamonds, worth more than $1.5 million, were stolen before the Australian Jewellery Fair, which opened on the weekend.
Police are investigating whether the precious stones disappeared en route to the fair or from an exhibition centre at Darling Harbour in central Sydney.
Event organiser Gary Fitzroy says he is mystified, given the tight security measures put in place.
"It's a little bit difficult over a large exhibition space to establish exactly where, if on site, it's gone missing within the hall exactly," he said.
"Our security procedures at the fair are recognised around the world as one of the strictest and the best, and by our surveillance tapes and the tapes surrounding the venue itself, we're hopefully going to shed some light on that."