Carnival time in Rio

A golden Queen Cleopatra bathing in milk, a female dancer pushing the limits of Carnival tolerance, and the high-kicking Moulin Rouge troupe kept 70,000 spectators in Rio's Sambadrome buzzing through to dawn.

Behind the scenes, next to a putrid canal and out of sight of the throng, the near perfect symmetry and order of the parades seemed a world away as the Samba schools frantically prepared for their annual coming-out show.

Stewards dressed in bow ties scampered here and there fixing last-minute wardrobe malfunctions and trying to hold back the tide of Brazilian tardiness and high spirits.

Enterprising vendors from nearby slums dangled ice boxes full of beer over a wall for nervous performers seeking a drop of Dutch courage.

Like a scene from Alice in Wonderland, performers dressed as 19th century nobles, wide-skirted "Baiana" dancers, and musical notes mingled as they sought their starting positions, practiced their lines or enjoyed a last-minute cigarette.

"People who have never paraded don't understand they need to be here in front instead of chatting," fumed 47-year-old Malucia Camacho, who was in charge of a "wing" of about 80 costumed dancers for the Mocidade Samba school.

"It's not a lack of practice, it's because they like turning up late and don't like to work. They are undisciplined," she added, before bustling off to chide a group of nobles.

Nearby, a musical note relieved himself against a wall.

The nationally televised annual parades featuring up to 5,000 dancers each and near-naked Carnival queens is a serious competition for the top Samba schools, judged on choreography, atmosphere, organisation, and singing among other points.

A disorganised wing or a faulty float can cost a school the tile and bragging rights over the next year.

"A bit of my wing broke and my costume is too tight," said Daniella Cremer, a raven-haired 25-year-old model and dancer, about half an hour before being winched by a crane on to the front of one of Mocidade's floats.

"If something falls off, I'll just keep going to the end."

Last year a school was famously disqualified when a tiny strip of material, called a "tapa-sexo", covering its top dancer's crotch fell off.

A Mocidade dancer, Dani Sperle, may have taken the record for the smallest tapa-sexo on display in the Sambadrome on Monday with a 3 cm (one inch) wisp of material, Brazilian media breathlessly reported. She appeared at the preparation area bare-breasted wearing just a headdress, necklace and boots.

Other omens were not looking good for Mocidade. During the last-minute preparations, its main parade designer was run over and injured by one of the floats, which also briefly caught fire.

Undeterred, 57-year-old steward Francisco Dos Santos drew on a cigarette and reflected on the importance of a good result.

"We're going to go out there with enthusiasm in our blood and get this title. We've deserved it for a long time," he said.

Moments later, fireworks boomed and Mocidade was on the move, parading past a still noisy crowd at around 3am, including Brazilian President Luiz Inacio Lula da Silva.

Its parade went smoothly, but others suffered mishaps. A dancer in the French-themed parade with cancan performers from Paris' Moulin Rouge fell over and an electrical fault left its Eiffel Tower in the dark. That parade was also invaded by a bemused-looking Labrador.