Watford face a docking of points over their sale of Danny Graham to Swansea City.
The Sun says Graham's £3.5million move from Watford is at the centre of a sensational disciplinary case.
Striker Graham and the Swans are not under suspicion but Championship promotion-chasers Watford and former owner Laurence Bassini are both in hot water with the Football League.
Watford have been charged with breaking third-party investment rules in relation to the 2011 Graham deal and with breaching another financial regulation.
If found guilty, the Hornets could face a points deduction.