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.
An NCA statement said: "Officers from the NCA have been actively pursuing a number of lines of inquiry in this ongoing investigation.
"The investigation began following receipt of material from the Sun on Sunday. It remains ongoing and we cannot provide further detail at this stage."
The tabloid reported that an undercover investigator met ex-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.
Match-fixing controversies
Soccer - FA Carling Premiership - West Ham United v Crystal Palace (01 of08)
Open Image ModalIn February 1999, a Malaysian-based betting syndicate was caught attempting to install a remote-control device to sabotage the floodlights at Charlton Athletic's ground with the aid of a corrupt security officer. If the match had been abandoned after half-time, the result and bets would have stood... (credit:PA)
Selhurst Park/floodlights failure(02 of08)
Open Image ModalSubsequent investigations revealed the same gang had been responsible for previously unsuspected "floodlight failures" at West Ham's ground in November 1997 and a month later during Wimbledon's match with Arsenal at Selhurst Park. (credit:PA)
Former South African cricket captain Hansie Cronje(03 of08)
Open Image ModalCAPE TOWN, SOUTH AFRICA - JUNE 15: Former South African cricket captain Hansie Cronje raises his hand to take the oath prior to testifying before the King Commission of Inquiry into allegations of cricket match-fixing in Cape Town 15 June 2000. Cronje confessed to pocketing large sums of money during a five-year flirtation with bookmakers and vowed that he would not play representative cricket again as punishment. (Photo credit should read ANNA ZIEMINSKI/AFP/Getty Images) (credit:Getty Images)
Hoyzer Sentenced to Two Years(04 of08)
Open Image ModalBERLIN - NOVEMBER 17: Former German soccer referee Robert Hoyzer leaves court after receiving a two-year and five-month sentence November 17, 2005 on the tenth and final day of hearings in Berlin, Germany. Hoyzer took payments from a Croatian-led betting ring to manipulate four soccer matches in one of Germany's worst-ever soccer scandals. (Photo by Sean Gallup/Bongarts/Getty Images) (credit:Getty Images)
Juventus' general director Luciano Moggi(05 of08)
Open Image ModalBari, ITALY: Juventus' general director Luciano Moggi phones as he leaves the San Nicola stadium in Bari after the Italian serie A football match Reggina vs Juventus, 14 May 2006. Luciano Moggi resigned after Juventus claimed their 29th Serie A title with a 2-0 win away to Reggina on the final day of the season. (credit:Getty Images)
(06 of08)
Open Image ModalIn July 2007 it was revealed NBA referee Tim Donaghy had gambled on 10 to 15 games, including games which he officiated. Donaghy was sentenced to 15 months in federal prison. (credit:Getty Images)
Spot-fixing, 2010(07 of08)
Open Image ModalUndercover reporters from News of the World secretly videotaped Mazhar Majeed accepting money and informing the reporters that fast bowlers Mohammad Asif and Mohammad Amir would deliberately bowl no balls at specific points in England's innings.The no balls were duly bowled at the exact stages predicted, and the International Cricket Council (ICC) banned Asif, Amir and Salman Butt for terms of between five and 10 years.In November 2011, Butt and Asif were found guilty by a London court on criminal charges relating to spot-fixing. Amir and Majeed had entered guilty pleas on the same charges. All four were given prison sentences, ranging from six months to 32 months.
Snooker - Stephen Lee Filer(08 of08)
Open Image ModalStephen Lee was banned for 12 years after being found guilty of seven match-fixing charges earlier this year. (credit:PA)
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 Portsmouth FC said that Sodje no longer played for the club, but that it would co-operate fully with any investigation if it was approached by the authorities.
It was also claimed that Oldham Athletic player Cristian Montano failed to get a yellow card in return for money in a match against Wolverhampton Wanderers on October 22 and offered to take part in another rigging incident.
Oldham said it would carry out an immediate internal investigation into the allegations.