Players' union FIFPro has told players from Czech club Banik Most to refuse to take a lie detector test after they were suspected of match-fixing.
The second division side have lost nine games in a row and FIFPro say the players have not been paid since March.
Now the club is considering making them take lie detector tests.
"Most's directors are treating their players as suspects, even though there appears no clear evidence," said FIFPro.
"Players are often the victims of match-fixing. Professional footballers could be involved, but match-fixing rarely starts with the players."
FIFPro added that the use of lie detectors was not efficient in any case.