RIO DE JANEIRO • A scene in the Rio Olympics' opening ceremony that spectators at a rehearsal thought depicted an attempted mugging of supermodel Gisele Bundchen sparked a bizarre polemic in Brazil on Monday.

Details are top secret ahead of Friday's ceremony.

However, leaks, following a dress rehearsal at Rio's Maracana stadium on Sunday, included multiple reports of a skit in which a mugger attempts to rob the Brazilian supermodel before police intervene and she forgives her assailant.

The ceremony's organisers lashed out at the reports, saying they were inaccurate and violated requests to keep the content of the extravaganza under wraps until the last moment.

Brazilian newspapers, however, quoted witnesses saying that they were sure that the scene showed an attempted street robbery - a surprising choice in an Olympic host city plagued by real-life crime.

According to Folha de Sao Paulo daily, Bundchen struts out to Girl From Ipanema, a classic celebrating a beautiful, young woman of Rio, and is "assaulted by an actor".

"The final message from the scene, however, will be peace," the report said.

The Olympic organising committee said "there is no robbery", declining to explain further.

However, in a new twist late on Monday, Lauro Jardim, a columnist for Globo newspaper, said that the controversial scene was being axed.

Meanwhile, Marco Balich, the opening ceremony's executive producer, revealed that it will break with the recent tradition of large-scale and expensive shows, featuring a low-emission cauldron and an "analogue" experience.

"This is not an opulent event given the (economic) situation in Brazil," he said.

"It does not have the grandiosity of Beijing, the huge special effects of Athens, the eccentricity and technological skills of London. It is an analogue opening ceremony."

The show, expected to cost about half the US$42 million (S$56.3 million) spent by London in 2012, is based on the themes of sustainability, the Brazilian smile and "gambiarra", the ability to keep functioning with makeshift fixes.

The name of the final torch- bearer who will light the cauldron is not known. But the cauldron will not be like past big structures with huge flames visible for kilometres.

"It will be a low-emission cauldron as it would be an oxymoron to talk about sustainability and then burn massive amounts of gas," Balich said. "It is a small burner with a kinetic sculpture."

Some 4,800 people will take part in the opening ceremony along with about 11,000 athletes, who will, due to the lack of a track, gather at the centre of the legendary football arena.

AGENCE FRANCE-PRESSE, REUTERS