Seven more players from Football League clubs in the North West have been arrested in connection with alleged spot-fixing.
Tranmere Rovers players Ian Goodison and Akpo Sodje were among six footballers arrested in January linked to the betting investigation.
The National Crime Agency today confirmed six players had been rearrested after "new evidence" came to light.
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 agency said.
A brief statement on Rovers website says: “Tranmere Rovers Football Club are aware of reports regarding Ian Goodison and Akpo Sodje.
“As this is an ongoing legal matter, the club are unable to make further comment.”
The NCA would neither confirm or deny that the Rovers pair had been rearrested.
In December, the original six suspects were held by police as part of the inquiry, prompted by information passed on by a Sunday tabloid, and were bailed to return on April 8.
The Sun on Sunday 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.
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.
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 that said: " The FA has been made aware of developments in relation to an ongoing NCA 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."
On Monday, Tranmere's suspended manager Ronnie Moore was charged with misconduct in relation to breaching betting rules.
Moore, who has been under investigation by the FA for six weeks, has until next Tuesday to respond to the charges.