The Brazilian government's data on water pollution in Rio de Janeiro show water near where triathletes are preparing to compete this weekend is "unfit" for swimming.
The designation is available on the website of the Rio de Janeiro state's environmental agency.
The most recent pollution reading was taken from a sample this past Monday. The environmental agency didn't respond to requests for comment.
The area that has been ruled unfit for swimming is near where an Olympic qualifier and Paratriathlon event begin Saturday. Athletes are already getting in the water as they prepare for the event.
The area has been deemed unfit on eight previous occasions this year.
On Thursday, The Associated Press released the results of a five-month investigation into Rio's waters. It showed that Olympic venues are rife with disease-causing viruses and bacteria.