Germany's 49er class competitor Erik Heil, who finished third with team-mate Thomas Ploessel in the test event, revealed in a blog post how he was told by a Berlin hospital that he had been infected by multi-resistant germs.

"I have never in my life had infections on the legs," Heil said.

"I assume I picked that up at the test regatta.

"The cause should be the Marina da Gloria [on Guanabara Bay] where there is a constant flow of waste water from the city's hospitals."

In a statement, the International Sailing Federation (ISAF) said they are "aware" of his illness, and are now working closely with the Deutscher Segler Verband, the German Member National Authority, to ensure he fully recovers in advance of a busy period that includes the ISAF Sailing World Cup Final and 49er World Championships.

Speaking on the final day of the test event, ISAF chief executive Peter Sowrey did say the event could be moved further out into the Atlantic in order to ensure cleaner water, but subsequent messages have been more supportive, with the latest statement expressing confidence the venue "will be ready to host 380 sailors during the Olympic Sailing Competition in one year's time".

Both Rio 2016 and IOC officials have repeatedly insisted there is no risk, vowing to jump in the Bay themselves in order to demonstrate its cleanliness. 

After South Korean windsurfer Wonwoo Cho was taken to hospital during the week-long test event, with his coach Danny Ok claiming the cause was "probably from the water" at Guanabara Bay, and 15 members of the United States rowing team being taken ill during that sport's test event earlier in the month on the Lagoa Rodrigo de Freitas, however, it is getting harder for the authorities to claim there is no risk for athletes competing in water-based sports in Rio de Janeiro.

One of the courses was also closed during the test event due to two days of problems with rubbish littering the course, with Rio de Janeiro authorities having reportedly removed 3.5 tonnes of floating rubbish from the Bay on each day of the test event.

Despite an Associated Press report finding "major risks" of athletes contracting viruses from the Guanabara Bay water, only bacterial rather than viral tests have been undertaken on the Bay.

In a letter preportedly sent to the heads of 140 National Sailing Federations, Glenn McCarthy, a US-based blogger who has repeatedly criticised pollution levels, has strongly criticised officials for repeatedly taking words but no action.

"The jibber jabber over water quality tests is something to take everyone's eye off the ball," he said.

"No one has said there are lines drawn in the sand: If the parts per million exceed, 'This Amount' we must move the venue.

"Without limits defined, this is just a political sideshow.

"The 2015 Aquece Test Event has proven again that Guanabara Bay in Rio de Janeiro FAILS at the ability to provide a Fair Contest for all the worlds athletes.

"IOC, Rio 2016, ISAF your words of assurances have worn us out.

"Your continued statement that 'The athletes safety and health is our utmost concern' is beautiful propaganda and public relations to tell the media, but you have shown no ability to assure the safety and health of the competitors.

"It is clear that you do not care about the athletes.

"Your time has run out, it is time to move the Sailing Games out of Rio, NOW."

The issue is currently the biggest challenge for organisers with less than a year to go until the Olympics begin, with a possible move of the course further out in the Atlantic something which would detract from the spectacle and visual beauty of the course, which had been within site of the some of the host city's most famous landmarks.

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August 2015: IOC praise "fantastic" Rio 2016 amid vows to jump into Guanabara Bay to prove water safety
August 2015: Fifteen members of US team taken ill following World Junior Rowing Championships on Rio 2016 course
August 2015: Rio 2016 sailing venue will be safe for athletes during Olympics and Paralympics, insists Bach