TOKYO (REUTERS) - Organisers of last week's diving World Cup in Tokyo have hailed the "successful" staging of the event after implementing strict Covid-19 countermeasures for the more than 400 participants.

In what was seen as a dress rehearsal for bringing in international athletes for the Olympics during the pandemic, the diving World Cup, held May 1-6 at the Tokyo Aquatics Centre, doubled as a test event for the upcoming Summer Games.

It and a volleyball test event between Japan and China, held May 1-2, marked the first time overseas athletes participated in test events since they were restarted last month.

"During the six-days of competition for this World Cup (attended by 224 athletes from 46 nations), strict Covid-19 countermeasures were put in place in order to ensure the health and protection of all those taking part in the event," the Tokyo 2020 organising committee and International Swimming Federation, Fina, said in a joint statement.

"All participants fully complied with the measures in place and Fina and Tokyo 2020 really appreciated their efforts," the statement said.

As previously announced, only one positive Covid-19 case was found, in a team official upon arrival in Japan. The person was quarantined immediately and no close contacts were identified by Japanese authorities, the statement said.

Overall there were 438 participants, including athletes, coaches and team officials, it said.

A marathon test event held in the northern city of Sapporo on Wednesday included six runners from overseas. On Sunday, a test event for track and field events was also conducted at the Tokyo Olympic Stadium, which featured 420 athletes, including nine from overseas. American sprint star Justin Gatlin, who won the 100m race, headlined the field and also praised the Covid-19 protocols, declaring that he felt "beyond safe".

World Athletics president Sebastian Coe said Tokyo organisers had delivered both on an operational level and in their Covid-19 precautions.