Geneva - Paris Saint-Germain chief Nasser Al-Khelaifi and FIFA's disgraced former secretary general, Jerome Valcke, were being questioned Monday by Swiss prosecutors probing alleged corruption in the attribution of football broadcasting rights.
The Swiss attorney general's office (OAG) described the interrogations as "final examination hearings" in the criminal investigations opened in March 2017.
Al-Khelaifi, who is also the boss of Qatari television channel BeIN Sports, is suspected of giving inappropriate gifts to Valcke - including rent-free access to a luxury property - in order to secure broadcast rights to prestigious events, including the World Cup.
Valcke, formerly ex-FIFA boss Sepp Blatter's right-hand man, is suspected of awarding those rights in exchange for bribes.
A third, unnamed suspect in the case - described by Swiss prosecutors as "a businessman in the sports rights sector" - is also accused of paying bribes to secure broadcast rights.
"All three suspects complied with the OAG's invitation to appear in person," the statement said.
It added that it was yet not clear whether formal indictments would be filed against any of the suspects or whether the cases would be abandoned.
In a statement, BeIN said the accusation that Al-Khelaifi had secured a favourable deal for the TV rights in the Middle East and North Africa for the 2026 and 2030 World Cups "has no single basis in law or fact".
"For this reason a motion to dismiss proceedings will be filed by Mr Al-Khelaifi's lawyers this week," the statement added.
Valcke's lawyer said the former FIFA official denies the accusations.
Al-Khelaifi was separately charged in May by French prosecutors in connection with Doha's candidacy to stage the world athletics championships.
French prosecutors are looking specifically at two payments of $3.5 million in 2011 by Oryx Qatar Sports Investment, a company run by Nasser's brother Khalid Al-Khelaifi, to a sports marketing firm run by Papa Massata Diack.
Diack's father Lamine Diack was president of the International Association of Athletics Federations (IAAF) from 1999 to 2015 and a member of the International Olympic Committee.
Valcke, who worked with Blatter from 2003-2015, has been banned from football for 10 years for failing to cooperate with investigators, the resale of World Cup tickets and inflated expenses.