LONDON (AP) The Latest on the developments in the Olympic world (all times local):
A 75-year-old Japanese equestrian athlete will not be able to become the oldest competing Olympian of all time in Rio de Janeiro because of an illness to his horse.
Kyodo news agency reported that Hiroshi Hoketsu was unable to meet the criteria to join the qualifying trials for the Japanese team.
Hoketsu, who made his Olympic debut in Tokyo in 1964 and at 71 was the oldest athlete to compete at the 2012 London Games, has been training in the Netherlands and Germany but hadn't been able to take part in competitions after his horse fell ill.
Hoketsu would have become the oldest athlete to compete at the Olympics had he qualified for Rio, overtaking Swedish shooter Oscar Swahn, who participated in the 1920 Antwerp Games at the age of 72.
Hoketsu was aiming for his fourth Olympics after also appearing at the 2008 Beijing Games.
Russian prosecutors say they will investigate allegations that the country's athletes doped at three recent Olympics.
According to spokesman Alexander Kurennoi, the Prosecutor General's office is examining possible ''doping by Russian athletes at the Olympics in Beijing, London and Sochi.''
Kurennoi, speaking to state news agency Tass, cited ''information published by various media and the World Anti-Doping Agency,'' but it was not immediately clear which specific allegations would be the focus of the investigation.
The former director of the Russian anti-doping laboratory told the New York Times last week that he provided athletes will banned steroids ahead of the games in London and Sochi.
Russian prosecutors previously investigated after a WADA panel report detailed systematic, state-sponsored doping in Russian track and field. That probe resulted in no criminal charges.