A drug-resistant "superbug" that is notoriously difficult to treat has been discovered by Brazilian researchers in the sea waters where sailing and windsurfing events will be held during the 2016 Olympics in Rio de Janeiro.

Usually found in hospital waste, the "super-bacteria" produces a so-called KPC enzyme which is not only resistant to antibiotics, but also poses a danger to swimmers by contaminating the water, the Associated Press reported.

"The illnesses caused by these micro-organisms are the same as those caused by common bacteria, but they require stronger antibiotics and, sometimes, can require hospitalization," said Ana Paula D'Alincourt Carvalho Assef, the study coordinator at Rio's renowned Oswaldo Cruz Institute.

"Since the super bacteria are resistant to the most modern medications, doctors need to rely on drugs that are rarely used because they are toxic to the organism."

"Carriers can take these resistant bacteria back to their own environments and to other people, resulting in a cycle of dissemination," said the institute, which is affiliated with Brazil's Health Ministry.

The bacteria was discovered after researchers took samples from Flamengo beach and several locations along the Carioca River, Rio de Janeiro, The Instituto Oswaldo Cruz, Brazil's most respected health research institute, said, adding that it wasn't clear how the bacteria may have gotten into the river.

Among the spots is where the river flows into the city's Guanabara Bay, site of the 2016 sailing and wind surfing events, UK MailOnline reported.

Although there have been no cases of infection resulting from the contaminated water yet, residents have been cautioned to take extra care since the superbug can cause urinary, gastrointestinal and pulmonary infections.

Rio, a city of some 10 million people, has nearly 70 percent of sewage spilled raw into the waters of Guanabara Bay, making the state of water quality a major worry ahead of the 2016 summer games.

Although organizers had promised to reduce the amount of sewage and garbage in Guanabara Bay by 80 percent in its Olympic bid, critics insist little has been done.

In June, Rio Mayor Eduardo Paes admitted that the target would not be met, BBC News reported.

"I am sorry that we did not use the games to get Guanabara Bay completely clean," said Paes.

Meanwhile Ben Remocker, a former member of Canada's Olympic sailing team who represents athletes in two sailing disciplines, called the findings "serious for our athletes."

"We're going to be troubled by this," he said, adding that he didn't believe the possible health risks would dissuade sailors from taking part in the games.

"I think the sailors are probably going to cross their fingers they aren't going to get sick."