Work will not resume on the programme to try to clear the venue for sailing until the project has been "optimised and the fleet expanded".

Water pollution remains a major concern for organisers with just 502 days to go until the Games are due to begin.

Improving levels had originally been a major part of the Rio 2016 legacy plans but there has been little sign of this promise being fulfilled. 

Sewage and contamination remains the longer-term problem but removing physical debris has been identified as the immediate target.

A meeting took place place earlier this month between International Olympic Committee and International Sailing Federation (ISAF) officials.

A Dutch Research Institute has been hired to create a forecasting system to identify areas where debris-levels are particularly high, which can therefore be targeted by collectors.

But the project has been postponed due to the lack of ecoboats from which the rubbish can be collected.

"At the moment, the ecoboat operation is suspended and it will be readjusted in order to attend the cleaning needs of Guanabara Bay," a spokesman for the Rio State Department of the Environment (SEA), the body responsible for pollution concerns, told insidethegames.

"The ecoboat project will return after it has been optimised and the fleet expanded.

"SEA decided to suspend its operation, because the fleet of 10 ecoboats wasn´t reaching the goal to collect 45 tons of rubbish per month and it also used to cost BRL$300,000 (£62,000/$92,000/€86,000) per month."

Despite the concerns, a test event on Guanabara Bay last summer was widely seen as a success, with a second test event planned for this August ©Getty Images



Yet, considering how close the Games now are, it appears critical this suspension of activity ends soon.

Some experts have claimed the tight timeline deems cost-related concerns irrelevant. 

The spokesman claimed the Department is currently developing a project to install new ecobarriers, with "more robust structures, based on positive experiences around the world". 

Several other possible solutions have been suggested, with United States inventor Scott Weiss having sent a letter, seen by insidethegames, to both the ISAF and International Swimming Federation calling for his product, the "Parachute Skimmer" to be used to help clean the water.

The device is a tool that collects floating debris, algae and pollution without using chemicals, Weiss has claimed.

It has been tested and recommended for use by the US Coast Guard and used in the clean-up operation following the Gulf of Mexico oil spill in 2010. 

On a smaller level, it is also used by pond maintenance experts, waterparks, marinas, resorts and hotels to remove debris and algae.