Adam Johnson, 27, was arrested yesterday whilst officers searched his £1.8 million home in County Durham.
The footballer- who has played for England- has been suspended from Sunderland ahead of their match against Hull in light of the arrest.
Adam’s mother-in-law spoke out in defence of her son following the police raid.
“He is 100 percent innocent and we will stand by him.
“He hasn't been found guilty of anything. He is a great lad and has not done anything wrong. This is a horrible situation.”
Adam recently became a father for the first time when partner Stacey Flounders gave birth to a daughter, Ayla Sofia, in January.
Stacey is reportedly standing by Adam following his arrest.
A Durham Police spokesperson said last night: “A 27-year-old man was arrested earlier today on suspicion of sexual activity with a girl under 16. He has been released on police bail pending on-going investigations.
“A blank firing pistol, which replicates the sound of real gunshots but does not require a licence to own, was also recovered during a search of the property.”