Tokyo Olympic and Paralympic staff and workers, including those from overseas, will be required to regularly self-collect saliva samples for COVID-19 testing, officials familiar with the games' planning said Thursday.

Instead of setting up special facilities to collect the samples, organizers plan to distribute containers for submission at one of around 60 locations, including hotels and venues, said the officials, who spoke on condition of anonymity.

The organizing committee of this summer's games estimates that the number of overseas officials and workers can be reduced to 78,000, less than half the initial figure, as a measure to prevent the spread of the coronavirus.

They include members of the International Olympic Committee, international sports federations, the press and those working for national Olympic committees and sponsors.

About 15,000 Olympic and Paralympic athletes, as well as their coaches, will be screened for the virus on a daily basis, in principle, under supervision at a sample collection center to be set up in the athletes' village.

But the organizers have determined that it would be difficult to do the same for non-athletes as they will be much larger in number and sample collection centers will likely be overcrowded.

How frequently the 78,000 visitors and Olympic workers from Japan would have to be tested for the virus depends on their proximity to athletes, according to the current plan.

The results of the saliva-based tests will be available within 24 hours of the submission of samples, and individuals with a positive COVID-19 result will be tested again, according to the officials.

To prevent tampering, the organizers are considering having officials and workers collect samples together in a group and supervise each other, they said.

The organizing committee had expected a total of around 180,000 officials and workers from foreign countries prior to last year's one-year postponement of the Olympics and Paralympics due to the pandemic.

The IOC and other organizers have been asking participating bodies to cut the number of people entering Japan as part of efforts to realize a safe Tokyo Games.

Those who will have regular contact with athletes will be tested for the virus on a daily basis, in principle, while others will be screened every four or seven days depending on their roles after being tested each day for the first three days, according to the plan.

As Japan is facing a fourth wave of infections, the public is concerned that an influx of people from abroad could worsen the situation.

With the Olympics scheduled to begin on July 23, the organizers have already decided to hold the games without spectators from abroad to help prevent the spread of the virus.