Tokyo, Seven more people from the All Japan Judo Federation (AJJF) have tested positive for coronavirus, bringing the total number of infections within the federation to 16.

Japan's judo governing body said that those infected consist of 12 men and 4 women, including managing director Soya Nakazato, reports Xinhua news agency.

The virus has actually paralysed the organisation since nearly half of the 39 staff members have tested positive and as of last weekend, 24 had developed symptoms of the pneumonia-causing virus, including fever, and 18 had taken a PCR test.

AJJF President Yasuhiro Yamashita, also chief of the Japanese Olympic Committee, apologised for the inconveniences, citing "inadequate measures" have been taken to prevent the spread of infection at an early stage.

The first positive case in the AJJF was confirmed on April 4, four days after a meeting at the federation's headquarters in Tokyo's Bunkyo Ward. But AJJF said that it was unclear when and where the staff members had got infected.

"It might be through work contact or on the way to work," read a statement.

It was another heavy blow to Japan's sports society following the postponement of the Tokyo Olympic Games on March 24.

The Osaka Evessa basketball club in Japan's B League Division 1 has reported 13 positive cases since early April, including 11 players.

The Japan Sumo Association also announced the first wrestler to have tested positive for the new coronavirus last Friday.

The federation closed the headquarters in principle from March 30, but a meeting was held there the following day which Nakazato attended.