Alicante-based club Hercules stand accused of paying a rival team's goalkeeper to throw a match last season and help them secure promotion to the top flight.
Hercules deny any wrongdoing but government lawyers and the Spanish football federation (RFEF) are seeking official access to taped phone conversations and other evidence from a separate investigation that have been widely published in local media.
It is a worrying state of affairs for a professional league that proclaims itself the world's best and which boasts a large proportion of the game's top players and hugely rich and successful clubs like Real Madrid and Barcelona.
However, the national team's victory in South Africa offers a unique chance to tackle the problems afflicting football and the authorities should use the momentum generated by the World Cup victory to put their house in order, analysts have said.
"There have always been rewards for winning but having them for losing is a very serious matter," Placido Rodriguez, a professor of economics at Oviedo University and a former chairman of La Liga club Sporting Gijon, told Reuters.
"If the evidence (against Hercules) proves correct we must show no mercy to the cheats."
"In that sense, domestic Spanish football has never been in a worse state," Gay told Reuters.
The 20 clubs in the top flight had total debts of 3.526 billion at the end of the 2008/09 season, with Real Madrid leading the way with 683 million, according to a study Gay published in May based on clubs' accounts.
