A French financial prosecutor has accused the son of the former International Association of Athletics Federations president Lamine Diack of 'large-scale' corruption.
The investigation was initially launched to scrutinise the awarding of the 2020 Olympic Games to Tokyo, Japan -- but now also encompasses the 2016 Games in Rio de Janeiro, Brazil.
Police have also searched the house of the president of the Brazilian Olympic committee on Tuesday in relation to bribery surrounding the awarding of last year's Games.
"The investigations revealed a large-scale system of corruption around Papa Massata Diack, son of Lamine Diack, IAAF president and influential members of the International Olympic Committee (IOC)," the financial prosecutor's office said in a statement.
"There are several consistent indications that payments have been made in return for the votes of IAAF and International Olympic Committee members over the designation of host cities for the biggest global sporting events," it added.
Lamine Diack, who hails from Senegal, was appointed president of the IAAF in 1999. His term has been blighted by allegations of corruption.
Earlier this week, French newspaper Le Monde claimed that Papa Massata Diack received a payment of $1.5million from a company linked to a Brazilian businessman -- just three days before Rio were awarded the 2012 Games.