Durham Police have taken action against a man who was allegedly harassing Adam Johnson's teenage victim online.
Sky Sports News HQ understands they have issued a harassment warning to Steven Knox, 29, after Johnson's victim was put under a "considerable deal of distress and harassment".
It is understood that Knox is the former partner of Johnson's sister Faye.
A Facebook page that has nearly 5,000 followers has been set up in support of Johnson, who was found guilty earlier this month of child sex offences.
The former England and Sunderland player, 29, is due to be sentenced at Bradford Crown Court on Thursday after he was found guilty of one count of sexual activity with a child on March 2.
He was cleared of one further count of sexual activity with a child.
Prior to the trial, Johnson pleaded guilty to charges of kissing and grooming the same girl, who was 15 at the time of the offences.
Meanwhile the FA have confirmed they are releasing a public film on child protection on the eve of his sentencing.
The video will not contain direct messages about his trial but has been produced in light of his case. It will warn about the potential dangers when working with children and outline how to safeguard children in sport.
The film will not be mandatory for players to watch but it will be available on the FA's website and sent to county FAs as part of an awareness campaign.