The Olympic mixed relay triathlon competition will be held as scheduled at 8 a.m. (0600 GMT) in Paris on Monday, organisers said in a statement after testing the water quality of the River Seine.
Training sessions for the swimming leg of the triathlon were cancelled due to poor water quality in the Seine and the men's event was put back to last Wednesday, taking place on the same day as the women's.
Organisers confirmed late on Sunday that the relay would take place, despite cancelling Sunday's training.
"Following requests from the triathlon teams to give the athletes more time to prepare for the upcoming mixed relay competition, a meeting was held today Aug. 4 at 7 p.m. to review the water quality results," World Triathlon and the Paris Games Organising Committee said in a joint statement.
"During this meeting, World Triathlon took the decision to confirm the mixed relay competition, scheduled for Monday 5 August at 8am."
Belgium, however, will not take part after one of their athletes, Claire Michel, fell ill, the Belgian Olympic Committee (COIB) said.
"Claire Michel, a member of the relay team, is unfortunately ill and must withdraw from the competition," the COIB said in a statement.
"The COIB and Belgian Triathlon hope that lessons will be learned for future triathlon competitions at the Olympic Games.
"We are thinking here of the guarantee of training days, competition days and the competition format, which must be clarified in advance to ensure that there is no uncertainty for athletes, entourage and supporters."
The COIB released an updated statement to clarify that Michel was back in her room at the Olympic Village.
"We have seen various statements in national and international media with incorrect information," the later statement said.
"Please note that Claire Michel has not been in the hospital for four days. Furthermore, she was not hospitalised prior to today.
"It is correct that she was taken to the polyclinic in the Olympic Village earlier today for treatment."
World triathlon said it had not heard from the Belgium team.
"The team has submitted their team declaration, chose their position on the pontoon this morning and checked-in their bikes also this morning. We have not received any other communication form them," a World Triathlon spokesperson said.
Paris 2024 organisers did not immediately respond to a request for comment on Michel's illness.