Rio de Janeiro Governor Luiz Fernando Pezao has signed a deal with several Brazilian universities and research institutes to develop a plan for cleaning up the polluted waters of the city's sewage-strewn Guanabara Bay, where Olympic sailing events will be held.

Pezao on Monday hailed the deal as a "very important step" toward the long-promised cleanup, which has dragged on for more than 20 years with little progress.

As part of Brazil's Olympic project, authorities pledged to drastically cut the amount of raw human sewage in the bay before the 2016 games.

But an Associated Press investigation published last week revealed high counts of disease-causing viruses directly linked to human sewage in Olympic waters.

Seven universities, as well as several research institutes will develop the new cleanup plan.