Water bacteria cancels Tokyo 2020 paratriathlon test swim

swimming section of a paratriathlon test event for Tokyo 2020 was cancelled Saturday due to high levels of bacteria in water, latest in a series of difficulties over water quality and temperature.

Olympic organisers have won widespread praise for ir preparations but extreme summer heat and poor water quality have brought headaches at practice events, with less than a year to go until opening ceremony.

International Triathlon Union (ITU) shelved swimming leg after tests showed levels of e-coli more than double acceptable standard.

70 paratriathletes instead competed in a duathlon format with two runs and a bike race.

"I'm so sorry for athletes that we could t prepare competition conditions effectively," Shinichiro Otsuka, managing director of Japan's Triathlon Union, told reporters.

"It was regrettable," he said, vowing to step up preparations for Sunday's Mixed Relay.

Former British paralympic triathlete Clare Cunningham tweeted that Saturday's decision to abridge race was "disappointing for all".

Read tweet here:

It was latest setback at a test event for Olympic organisers after extreme temperatures women's triathlon run was cut short due to extreme heat in Japanese capital on Thursday, with French triathlete Cassandre Beaugrand was taken to hospital for suspected heatstroke.

Around a dozen competitors and spectators also fell ill at a rowing test event, also due to high temperatures, as Tokyo swelters through a deadly heatwave.

Competitors at a marathon swimming test event on Sunday complained of smelly water and high water temperature at Odaiba Bay, location for long-distance swimming and triathlon.

Organisers are desperate to avoid embarrassment of 2016 Olympics in Rio when pool used for diving events turned an unsettling shade of green overnight.

Brazilian officials also had to scramble to clean up bay used for sailing and windsurfing that was plagued by sewer bacteria and filthy with rubbish.

In October 2017, Tokyo 2020 organisers were left red-faced after tests revealed levels of e-coli bacteria more than 20 times higher than international standards, sparking doubts about venue's safety.

At time, organising committee blamed prolonged summer rain that had brought pollutants from offshore for high readings between late July and early September.

A year later, organisers said that tests using underwater "screens" to filter water had successfully reduced bacteria levels at venue.

"We will keep doing our best to secure a safe and sound environment for athletes towards Games next year," Tokyo 2020 spokesman Masa Takaya said Saturday.