Footballers have been warned to report any approaches or information about match-fixing after it was confirmed Blackburn striker DJ Campbell has been arrested as part of a football spot-fixing investigation.
The 32-year-old is one of six people detained in an investigation by the National Crime Agency (NCA) after it acted on information passed to it by the Sun on Sunday newspaper.
Five people, including Campbell, have been bailed until April, and a sixth is still being questioned, the NCA said.
Simon Barker, assistant chief executive of the Professional Footballers' Association, said players had to protect themselves.
He told BBC Radio Five Live: "We would say to players 'if you hear of any information or you are approached then make sure you protect yourself by telling somebody at the club or the players' union or speak to the FA'.
"The regulations actually state if you are approached you have to report it to the FA.
"This has become a major issue and its something that goes across all nations and across all sports."
According to the Sun on Sunday, an undercover investigator met former Portsmouth player Sam Sodje, who allegedly said he could arrange for footballers in the Championship to get themselves a yellow card in return for tens of thousands of pounds.
The 34-year-old claimed he could rig Premier League games and even said he was preparing to fix matches at next year's World Cup in Brazil, the newspaper reported.
Portsmouth will hold a meeting with their players on Tuesday in the wake of the allegations but Pompey chairman Iain McIness said the betting industry's responsibilities should also be examined.
He said: "I think the gaming industry should be held to account. Somebody can sit on their laptop and check out of a bet, you don't even have to win the bet now. There is just too much of it.
"It's inevitable if you make betting as big a business as it is now available to sport in that depth, you are going to have a bunch of characters that are just going to do things you shouldn't be expected to do."
It also alleged that Oldham player Cristian Montano failed to get a yellow card in return for money in a match against Wolves on October 22 and offered to take part in another rigging incident.
Oldham confirmed Montano had been arrested and that the club had suspended him without pay while the investigation was ongoing.
Oldham manager Lee Johnson told the official club website: "Anybody who saw that report will have been devastated and sick to their stomachs.
"However, we have to let the authorities do their job and duties, and we cannot prejudice that."
Johnson added the club will have to wait for the results of the investigation before they can determine Montano's future.
He added: "It is disappointing how somebody can get themselves into that situation.
"The truth is that we don't know yet what has happened for him to be in the room talking about that."
In Campbell's case, detectives are likely to review a yellow card he received for a tackle committed in the first half of Blackburn's league game against Ipswich last Tuesday.
London-born Campbell began his league career at Brentford and went on to play in the Premier League for Birmingham, Blackpool and QPR.
He signed for Blackburn in July after previously joining the club on loan from QPR last February.
Another of the suspects was reported to be Sodje's brother Akpo, 33, who plays for Tranmere, who said they were aware of the allegations but would make no further comment.
The NCA is already carrying out a separate investigation into an alleged international illegal betting syndicate.
Michael Boateng and Hakeem Adelakun, both 22, were charged last week with conspiracy to defraud contrary to common law.
The pair, who played for Conference South club Whitehawk FC in Brighton, were dismissed by their club and will appear in court on Wednesday.
Two other men, Chann Sankaran, 33, from Hastings, East Sussex, and Krishna Sanjey Ganeshan, 43, from Singapore, were charged last month with plotting to defraud bookmakers and will also appear in court this week.