Russian tennis player Yana Sizikova has been released without charge following her arrest at the French Open in Paris on Thursday.
The 26-year-old had been taken into custody over match-fixing allegations during a game at Roland Garros last year.
She had been accused of “sports corruption” and “organised gang fraud”.
Prosecutors say the allegations centre on a match at Roland Garros last year. Sizikova was playing with partner Madison Brengle of the United States. The pair lost 7-6(8) 6-4 to Romanians Andreea Mitu and Patricia Maria Tig.
During the match, hundreds of thousands of euros were wagered on a break of serve during the second set at 2-2. During that game, Sizikova hit two double faults and lost her serve without winning any points.
The sports journalist Michael Kurn says Sizikova's arrest is the most high-profile case so far.
"It's a problem that was highlighted in 2003 while in 2011 Wimbledon organisers issued a list of people suspected to be involved match-fixing," Kurn says.
"It's an issue that the authorities want to stop because it does not send out a great message for the sport."