Three million pounds (NZ$5.8m) worth of jewellery destined to be worn by Rita Ora at the Cannes Film Festival went missing after a courier left her suitcase on the plane.
A woman charged with delivering the jewellery to the Kosovan-born British singer took a flight from London Luton airport to Nice on May 16 and left the plane without her coat and high-value cabin baggage.
According to police sources in France, she realised her mistake and tried to return to the plane, but it was too late, and it was already embarking on the return journey.
The airline, understood to be EasyJet, located the baggage and ensured it was kept safe until the flight landed back in England. They then transported the precious cargo to Heathrow airport where is was collected by police officers.
The costly items had been lent to Ora by jewellers based in London, but it is not known who at this stage.
The singer was in the south of France for a series of events and parties, but was seen in diamond earrings at Charles Finch's 10th annual Filmmakers dinner last Friday and wearing a striking diamond necklace the night before at a party hosted by Magnum ice cream.
The singer left Nice by private jet on Saturday afternoon and is back in the UK for the European leg of her world tour. She has already played in Australia, Japan and the United States, and is due to play at the O2 arena in London on Friday.
While in this instance the jewellery was recovered, Cannes has been hit by a string of high-profile heists in recent years.
In 2015, robbers pulled off a €17.5 million (£13 million) jewellery raid just days before the Film Festival started.
The robbery took place when top jewellers ship in their most prized gems to adorn Hollywood celebrities on Cannes' Croisette.
Despite high security, one robber in an 'old-man' mask and carrying a pistol burst into a Cartier boutique, letting in two accomplices with scarves around their faces, while a fourth man stood guard outside.
The Cartier store lies next to the luxury Carlton hotel - the scene of another daring jewellery raid in July 2013 that saw a lone thief make off with more than €140 million of gems, after breaking into the hotel through a door on the ground floor.
He left then vanished into the crowd without trace and has never been caught.
That same year, a thief broke into the hotel room of an employee of Swiss jewellers Chopard and made off with a €1.4 million haul while another escaped with a €1.9 million diamond necklace during a party at the exclusive Hotel du Cap-Eden-Roc near Cannes.
Rita Ora's management were contacted for comment.