Beijing 2008 Olympic champion Fernando Echavarri, his Nacra 17 catamaran class partner and 2011 470 world champion Tara Pacheco and coach Santi Lopez-Vazquez were all mugged in Santa Teresa, an up-market neighbourhood popular with tourists to the west of Guanabara Bay on which the Marina is located.

They were confronted by five people armed with two pistols, according to a statement released by the Spanish Sailing Federation.

A bag with money, documents and a camera was reportedly taken.

None of the victims were injured in the incident.

"Civil police are working to identify the authors of the crime and to recover the stolen objects," added a Rio de Janeiro police statement.

Ensuring the safety of athletes, spectators and all other personnel attending the Games is one of the priorities in a country notorious for petty crime.

Rio, despite being considered among Brazil's safer cities, has huge problems, particularly in favela neighbourhoods where shootouts between police and drug gangs are common.

Earlier in 2016, images surfaced of a number of daylight muggings carried out by a group of militant children, captured by a local businessman who used his camera to film the series of incidents from December to January.

But tourists and foreigners are also targeted in wealthier areas.

In May of last year, 57-year-old doctor Jaime Gold was attacked while cycling close to the Lagoa Rodrigo de Freitas lake upon which rowing and canoe sprint events will be held, later dying in hospital as a result of his injuries.

A 19-year-old French cyclist was also assaulted in the same district at a similar time of the year.

Earlier this month, retired football legend Rivaldo claimed anyone visiting for the Games will be “putting their lives at risk” due to the security situation.

Another problem is financial crime, with gangs known to target ATM machines used by tourists.

Brazilian and Rio 2016 officials claim the streets will be safer during the Games, with around 85,000 soldiers and police expected to be deployed during the Olympics - about twice as many as London four years ago.

The latest incident is not a good sign, however.

"The lack of security in Rio is one of the points that worries the teams," the Spanish statement added.

"Fernando, Tara and Santi want to forget what happened as quickly as possible and concentrate completely and exclusively on the training."