The incident took place close to the Olympic Park on the eve of the Rio Games.

Police in Rio de Janeiro said a Russian diplomat trying to repel an attempted robbery Thursday (Friday NZT) near the Olympic Park was involved in a shooting that left the assailant dead.

The Russian embassy denied any of its employees were involved in the incident.

Rio police said a Russian vice consul wrestled with a gunman who was trying to rob him, causing the weapon to go off and killing the criminal. In a statement to The Associated Press, the Russians refuted the police report.

"There must be a misunderstanding," the embassy said in an email on Friday afternoon (NZT).

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The Russian government also said its representatives are not armed.

It pointed out that consulate officials are "Russian citizens with Russian names," contrary to media reports that gave a Brazilian-sounding name.

Authorities did not officially identify any of the people involved in the incident, and only said the man who was attacked was a lawyer and a vice consul for Russia.

However, the Daily Mail reported that Marcos Cesar Feres Braga, a Brazilian lawyer who holds the vice-consul post at the Russian consulate, grabbed his assailant and pulled him into his car, before shooting him dead with his own gun.

The O Globo newspaper and other local media said the Russian diplomat practiced Jiu-jitsu. They reported that he was driving with his wife and daughter when he got stuck at a traffic jam on a main highway of Barra da Tijuca, home to the Olympic Park. Two gunmen in motorcycles attacked, media said. The police only talked about the assailant, who was killed.

"The vice consul got into a physical confrontation with the aggressor, and during the fight, the assailant's gun was fired several times," said the police statement. The homicide unit opened an investigation.

But the G1 website, part of the Globo media group, said a statement provided by the police said the gun went off in the struggle, striking the assailant who died at the scene.

The mugger struck at around midday on Thursday as the car was waiting for traffic to start moving again after the Olympic torch relay had passed by on Avenida das Americas in the Barra da Tijuca district of Rio, close to the Olympic Park and athletes' village.

The mugger's body lay on the road for several hours as police underwent investigations.

One witness said the mugger, named as Leonardo Lopes Batista, shouted, "you've lost, hand over your watch" before breaking the car window with his revolver.

An accomplice fled after seeing his partner suddenly hauled inside the diplomat's car.

In a statement, Rio's 31st Military Police Battalion, which investigated the incident, said Braga acted quickly pulling the man inside the car before taking his revolver and shooting him.

Rio's Homicide Police Station said investigators were still at the crime scene, more than five hours following the shooting.

"The man involved is a lawyer and also the vice-consul of Russia. He is Brazilian and a native of Rio de Janeiro," the Daily Mail quoted a spokesman as saying.

"He is not part of or has any relation with the Olympic committee of Russia which is in Rio de Janeiro for the Olympics."

The shooting comes amid heightened security during the Olympics, with 80,000 members of the Brazilian military bolstering police resources.

- AP, Reuters