Police are reviewing security camera footage in their investigation of the theft of more than 500 jewels from a trade fair in Sydney, the Australian Broadcast Commission reports.

Officers reportedly say that they believe the uncut diamonds, worth more than $1.5 million, were stolen either en route or during the Australian Jewellery Fair, which was held Aug. 20-22 at the Sydney Exhibition Centre, in Australia’s largest city, ABC reports.

ABC reported that event organizer, Gary Fitzroy, is “mystified” by the theft.

“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 told ABC.

“Our security procedures at the fair are recognized 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,” he reportedly added.

JCK