An American couple found themselves embroiled in a legal nightmare with French authorities over the trafficking of a "national treasure" belonging to France following an episode of .

The trouble began for Phillip and Gay Courter when a French couple they had befriended, Gerard and Annette Petsy, asked them to safeguard a briefcase filled with gold bars while Gerard sought an American buyer.

The Courters kept the gold for 15 years before attempting to sell it on . Despite consulting with customs and filing the bars with the IRS after storing them in a safety deposit box, they found themselves in hot water.

READ MORE:

READ MORE:

Despite reassurances from their lawyers that they were not breaking any laws, the couple was arrested in England and since they didn’t have any UK currency on them to pay bail, they ended up in jail.

Reflecting on the bewildering series of events, Phillip shared with the New Yorker how they came into possession of the valuable ingots. He recounted how Gerard personally flew to Florida to deliver 20 gold ingots to them.

The father-of-three remembered: "He walks in and pops open this briefcase full of gold, and we're like, 'Oh my God'. Gerard was a crazy guy with so many irons in the fire," reports .

When Phillip showed his children the gold, they promptly ran off and started playing with them "like Legos". He laughed: "Honestly, we thought it was cool. We did ask a few questions.

"We thought, 'The British Museum is buying it, so it must be legit.'" However, it turned out the gold bars had originally belonged to Prince de Conty and went missing after his shipwreck in Brittany.

Archaeologist Michel L'Hour stumbled upon an online listing for the bars with a description that read: "Nearly identical to the bars from the wrecks of the French East India Company vessel Prince de Conty, and to the Dutch East-Indiaman Geldermalsen."

The listing included a link to an episode of Antiques Roadshow, where a French woman, later revealed to be Annette Petsy, showcased the bars.

This discovery led L'Hour and the French authorities to the Courters. While in custody, the Courters discovered that a French judge had issued arrest warrants for them over the trafficking of "national treasure belonging to France".

After being released on bail in the UK, they were unable to leave the country and stayed with acquaintances while fighting the charges, spending their savings on legal fees and borrowing from friends.

Their daughter told The New Yorker: "They were hollow shells of the people I knew."

Once they hired a French legal team, the Courters learned that the arrests could have been avoided if their US lawyers had understood certain aspects of French law. Their French legal team arranged an immediate deposition over Zoom, and they were formally charged with concealment of stolen goods and money laundering.

However, the judge lifted the extradition order and allowed them access to their passports so they could return home.

A trial has been scheduled for later this year. Their lawyer Gregory Levy told The New Yorker: "We will try to demonstrate that there was no criminal intention. They sold on eBay. When you want to traffic something, you don't go on eBay, right?"

Reflecting on the entire experience, Gay said: "Was our situation typical or unusual? How many people without our privileges or resources are being detained in foreign countries without charges?

"It is not an exaggeration to say that nothing in my life prepared me for this, and I am no longer the same person I was. The gold was a tiny fragment of our lives together – meaningless, until it wasn't."

Antiques Roadshow is available to watch on BBC iPlayer