Despite the June 8 victory, Santander were relegated to the third tier after dropping down to the second division at the end of the 2011-12 campaign and are struggling to stay afloat after several years of institutional turmoil.
"Racing has absolute confidence in the players in its squad and rejects any malicious report that calls into question its honesty and professionalism," the north coast club said on their website.
"The club is the first to want to clear up the situation and will immediately make itself available to UEFA and the LFP (Spanish professional league) to mount a thorough investigation of the facts published in the media," they added.
The fixing of games, particularly towards the end of the season, has long been an open secret in Spain though few individuals or clubs are ever held to account.
LFP president Javier Tebas said after being elected in April it must be the priority of the league to stamp it out and Spain needed to abandon a culture of "anything goes" that meant clubs trying to avoid relegation were buying games.
Tebas said on Thursday he believed the Santander-Hercules game was thrown.
"I believe it was clearly fixed and that is what the reports from UEFA and the betting firms say," he told an internet chat organised by website El Confidencial.
"What's more, other matches, both in the first and second division, are being investigated and that takes time," he added. "There will be news."
Match-fixing hit the headlines in February when investigators said they had uncovered evidence that hundreds of matches at club and national level had been fixed around the globe in a betting scam run from Singapore.
- Sports & Recreation