Where are the Louvre jewels now and can France get them back?
The group were professionals, Mr Brand believes, as demonstrated by the fact they were in and out of the Louvre so quickly. "You know, as a normal person, you don't wake up in the morning thinking, I will become a burglar, let's start with the Louvre," he said. "This won't be their first heist," he said. "They have done things before, other burglaries. They are confident and they thought, we might get away with this, and went for it." In another sign the professionalism of the gang is being taken seriously, a specialist police unit with a "high success rate in cracking high-profile robberies" has been tasked with tracking them down. Authorities have said they suspect the heist is linked to an organised crime network. Mr Brand says it means the perpetrators will likely have criminal records and be known to the police. Organised crime groups like these generally have two objectives, Paris prosecutor Laure Beccuau said. "Either to act for the benefit of a sponsor, or to obtain precious stones to carry out money laundering operations." Mr Brand thinks it would be impossible to sell the items intact, and he said stealing-to-order for a private collector is something that only happens in Hollywood films. "Nobody wants to touch a piece so hot," he explained. "You cannot show it to your friends, you cannot leave it to your children, you cannot sell it."