Austrian league leaders LASK Linz face possible punishment for violating health regulations by resuming full training, a move which incurred the wrath of their rivals.
The league investigation was triggered by a video tape of the training sessions, which was filmed without the club's knowledge and which allegedly showed a breach Austrian regulations for fighting with coronavirus pandemic.
Since 20 April, clubs in Austria have only been allowed to train in groups of up to six players. Full training will only be allowed from Friday. The championship is scheduled to resume on 2 June.
LASK has filed a burglary complaint claiming that a camera was smuggled in to spy on training sessions and that the perpetrators were themselves filmed.
LASK, coached by Frenchman Valerien Ismael, did not deny the accusations, acknowledging in a statement that "as shown by a camera illegally introduced during a night-time break-in, the rules of distancing were not strictly observed".
The case will be examined by the league's disciplinary bodies and the club could face sanctions.
Other top-flight clubs have reacted angrily.
"We are shocked and amazed," said Stephan Reiter, commercial director of defending champions Red Bull Salzburg, who regretted that not all clubs "are aware" of their "great responsibility".
Salzburg, six-time champions, are second in the standings, three points behind Linz.