Most of the investigation’s focus, however, was elsewhere. Europol described a wide-ranging network of fixing that struck at the sport’s core. Nearly $11 million in profits and nearly $3 million in bribes were discovered during the investigation, which uncovered “match-fixing activity on a scale we have not seen before,” Wainwright said.

“This is a sad day for European football,” he added.

Fixers typically seek to dictate a game’s result by corrupting the players or the on-field officials, and the Europol officials said Monday that roughly 425 people were under suspicion because of the investigation, with 50 people having been arrested. The scope of the investigation covered games from roughly 2008 to 2011.

An organized crime syndicate based in Asia is believed to be the driving force behind the fixing activity, which stretches across at least 15 countries, Europol officials said. Individual bribes were, in some instances, higher than $136,000, and fixers would place bets on the tainted matches through bookmakers in Asia.

Various matches in Africa, Asia and South and Central America were identified as suspicious, and Declan Hill, a Canadian journalist and the author of “The Fix: Soccer and Organized Crime,” said his reporting on the subject — which was included in Europol’s investigation — had not previously indicated such widespread fixing among national teams.

“That number, that 150 international games, says to me that it is not just players and officials that are being targeted,” Hill said in an interview. “It is also team officials. With that many instances, it seems clear that there is more organization where a team official is guiding something.”

Europol did not publicly identify the ringleader of the Asian syndicate, but several knowledgeable law enforcement officials later said on condition of anonymity that it was a man based in Singapore known as Dan Tan. They said Tan had been implicated in match-fixing cases dating to 1999. Interpol has issued an international arrest warrant for Tan, but Tan has not yet been detained.

The conclusion of Europol’s investigation comes after a torrent of high-profile match-fixing incidents. Last month, FIFA, the sport’s governing body, barred 41 players for fixing matches in South Korea; in December 2012 the president of the South African Football Association was suspended after FIFA determined that four exhibition matches before the 2010 World Cup had been fixed; and last summer, a complex match-fixing network was discovered in Italy, rocking that country’s high-profile professional leagues for the second time in six years. Italy also endured a vast match-fixing scandal in 2006.