Paris prepares 'spectacular' show featuring 3,000 dancers for Olympics opening ceremony

Music pounds through an empty hangar on the outskirts of Paris as dancers perform a few snatches of a top-secret routine in front of giant mirrors.

Audiences will get to see the fruits of their labours on July 26 when the opening ceremony of the Olympic Games is held in Paris.

The organisers promise something "spectacular" but their lips are sealed on the details.

A handful of journalists, including AFP, were able to attend just a few minutes of a rehearsal this month.

Neon lights and disco balls contrasted with the industrial chaos of the decrepit but immense hangar.

Such a huge space was necessary because -- for the first time in Olympics history -- the opening ceremony is not taking place in a stadium.

Instead, it will stretch across seven kilometres of the River Seine with more than 3,000 dancers performing 10 different routines on the day.

The section that AFP partly witnessed will include some 400, but nowhere is big enough for them to rehearse all at once so they work in smaller groups of around 50.

"It requires real organisation but we're getting there," said lead choreographer Maud Le Pladec.

"There won't be a single bridge in Paris without some dancers on it," she added.

Her aim is to show dance in "all its diversity", bringing together everything from classical to breakdance.

As the dancers' sneakers squeak around the floor, the head of the Olympics organising committee, Tony Estanguet, and the artistic director of the Games, Thomas Jolly, slip into the room to watch.

"Excellent, it makes you want to get involved!" said Estanguet.

No one is giving away any details, but Jolly says all the feasibility studies have been completed and the initial plan is going ahead with just a few minor modifications.

"It has taken concrete form since mid-March," said Jolly.

"The choreographies are set, the costumes have come out of the workshops, the music... we're ready!"