The general director of anti match-fixing organisation Federbet has said fixing is widespread in Spain's lower divisions.
Francesco Barranca warned that would continue to be the case unless the Spanish Football Federation (RFEF) took steps to eradicate it.
His comments came after Spanish police charged five people this week in a match-fixing investigation after third-tier side Eldense lost 12-0 at Barcelona B last Saturday.
Barranca said he believed some of Eldense's previous results were suspicious and told Cadena Cope radio: "We have monitored Eldense's case.
"We started to see that there were strange bets going on during the game at Cornella [who were 3-1 winners on March 19] and in four other games they played.
"For us it's not surprising because we see similar situations happen every week in third and fourth division games in Spain.
"Since the Paterna vs. Castellon [fourth-tier] game in December 2015 [under investigation for match-fixing], there are two or three games that are suspicious in Spain every week.
"In Spain's fourth division, fixing games is a common practice."
Barranca said a lot of money was bet on matches in the Spanish lower divisions, with much of that betting taking place in Asia.
"In one third division game in Spain, money moved in betting worldwide is around €1 million per game," he said.
"In Eldense's case alarm bells rang because in one game there were €500,000 in bets made at one bookmaker alone."
He said there was also "a lot of match-fixing going on, too, in the youth sector."
Two players, two coaches and the club general director of Eldense were charged by police with "corruption between individuals" and "belonging to an organised crime group" after Saturday's 12-0 defeat.
"To fix a game, you need a minimum of one player [to be involved], a goalkeeper," Barranca said.
"Although we are seeing more and more cases, including in Italy, of having 10 players in a given team involved in it."
Federbet will send a report to La Liga but urged the RFEF to do more, with Barranca saying: "Until the federation does something, match-fixing will continue."
RFEF officials said on Wednesday that disciplinary proceedings had been opened against Eldense.
"We will send a report to La Liga," Barranca added.
"I think after the investigation and people talking about the problem, players will now be frightened in this weekend's games."