Katie receives a tip-off that sultan1966 has been selling gems in the US.

After speaking to a buyer in New Orleans, she learns about an even bigger collection of gems offered by the same seller that have ended up in the Washington DC area.

Presenter: Katie Razzall

Ittai Gradel says he sold on some of the gems he thinks came from the British Museum.

A mission to hunt them down leads the team through the backstreets of Paris and to a small town in Germany.

Presenter: Katie Razzall

As news of the thefts breaks around the world, the boss of the British Museum turns on Ittai. Now he has to fight to clear his name.

And what of the thief? The museum shares details about how they think the thief covered their tracks. Peter Higgs is sacked and when Katie tries to learn more about him she discovers something unexpected.

Presenter: Katie Razzall

Archive: Sky News

The inside story of how ancient treasures were stolen from one of the world’s most renowned institutions. And how one man believes he caught a thief. Omnibus edition part one of two.

Presenter: Katie Razzall

Ittai is convinced he’s found his thief, but not everyone is so sure. “I mean, to me, it just sounds like a setup. It sounds like he’s being framed”, one former museum insider tells us.

Peter Higgs is a well respected curator, highly regarded for his expertise on the ancient world and known for helping to return stolen antiquities, not selling them on eBay.

When Ittai shares his evidence with the British Museum, laying out why he thinks Higgs is a thief, no one seems interested. Has he missed something?

Presenter: Katie Razzall

Archive: Galleries of the British Museum

For Ittai, the clues finally fall into place. Has he identified the thief?

Ittai Gradel long suspected someone was selling ancient gems that once belonged to the British Museum. But he had no idea when they were stolen or by whom.

Now a startling discovery leads him to believe the thefts are recent and that the thief is someone in a position of trust.

Presenter: Katie Razzall

A mysterious seller appears with a seemingly endless supply of ancient, precious gems at bargain prices. Collector and dealer Ittai Gradel snaps them up. But then a strange series of events starts to unfold.

From his home in rural Denmark, Ittai becomes suspicious about what is happening hundreds of miles away at the heart of the British Museum.

Presenter: Katie Razzall

People have called Dr Ittai Gradel a kind of Sherlock Holmes, if Holmes were Danish and obsessed with gems. He’s an antiquities dealer with an eye for stolen goods who will help unlock the mystery at the heart of this story.

When Katie meets him in London, he’s got something to show her - two ancient gemstones he believes belong to the British Museum.

But this whodunnit begins more than a decade ago as a man with a cardboard box wanders into an antiques market. He has some valuable treasure to sell.

Presenter: Katie Razzall

Archive: Sky News Australia

The inside story of how ancient treasures disappeared from one of the world’s most famous museums. And how one man believes he uncovered a thief.

What begins as a whodunnit turns into a global treasure hunt as Katie tries to track down the missing gems.

Archive: Sky News Australia