Sunderland dressing rooms at the Stadium of Light and their training ground have been raided by police.
The Daily Mail says Adam Johnson was arrested on March 2 at his £1.85million mansion on suspicion of having sex with a 15-year-old girl and was bailed until Wednesday.
As part of the probe, officers also turned up at the 49,000-capacity Stadium of Light and the 60-acre Academy of Light and scoured both dressing rooms as part of their hunt for evidence.
It is also understood that all Sunderland staff were called into meetings following Johnson's arrest and warned away from posting anything about it on social media and from speaking to the press.