Seven more players from Football League clubs based in the north west of England have been arrested in connection with alleged spot-fixing and another six rearrested over the claims.
The 13 footballers, aged between 18 and 30, are being interviewed at police stations across the country after they were held as part of an investigation into alleged bribery and money laundering, the National Crime Agency said.
In December the original six suspects were arrested as part of the inquiry, prompted by information passed on by the Sun on Sunday, and were bailed to return on April 8.
The tabloid reported that 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 also 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.
At the time Pompey said Sodje no longer played for the club but they would co-operate fully with any investigation if it was approached by the authorities.
It was also claimed 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 said they would carry out an immediate internal investigation into the allegations.
Blackburn striker DJ Campbell was confirmed to be one of the six players who were arrested in December.
A Football League spokesman said: "The Football League has been made aware that a number of arrests have been made in relation to an ongoing police investigation.
"We will provide our full co-operation to the relevant authorities. Given that it is an ongoing matter, we cannot comment further at this time."
The Football Association released a brief statement which read: "The FA has been made aware of developments in relation to an ongoing NCA (National Crime Agency) investigation, including a number of further arrests.
"We are liaising with the authorities in relation to these allegations. The FA will make no further comment at this time."
Preston said in a statement on the club website: "In response to media inquiries received, Preston North End Football Club can confirm that today, April 3 2014, the club has been contacted by the National Crime Agency in relation to a wide-ranging investigation into 'spot fixing' in football.
"There are no suggestions that any offences that might have occurred involved match-fixing.
"None of our employees have been charged with any offence at this time and until or unless this position changes we will be taking no further action nor making any further comment.
"All of our contracted employees are available for selection by the manager."