POLICE have warned they will deal robustly with any social media users who identify the victim of an alleged sexual offence involving a Premiership footballer.

The caution was given today (Wednesday, March 3) in the wake of the arrest of Sunderland winger Adam Johnson on suspicion of sexual activity with a 15-year-old schoolgirl.

The family of the star’s girlfriend Stacey Flounders have, meanwhile, said they are standing by him.

Miss Flounders, of Hartepool, gave birth to their daughter seven weeks ago.

Mr Johnson was arrested at his £1.5m house in Castle Eden, County Durham, yesterday and the Black Cats have suspended him pending the outcome of the police investigation.

Speaking to a national newspaper, Ms Flounders’ mother said: “Stacey and Adam are still very close and absolutely together.

“He is 100 per cent innocent and we will stand by him. He hasn’t been found guilty of anything.

"He hasn’t been found guilty of anything. He is a great lad and has not done anything wrong."

Durham Police confirmed yesterday that a 27-year-old man had been was arrested on suspicion of sexual activity with a girl under 16. He has since been released on police bail to March 18.

The force has reiterated that "anyone who identifies someone who may or may not be a victim of a sexual offence is committing a criminal act".

A police spokesman said: “Victims of sexual assault are guaranteed the legal right to lifetime anonymity and publishing any details, including on social media, which may lead to their identification, is contrary to the Sexual Offences (Amendment) Act 1992.

“Durham Constabulary wishes to remind social media users, and anyone else, who breaks the law that they will be dealt with robustly.”

Johnson had been due to travel with the rest of the Sunderland squad to Humberside this afternoon for tomorrow's important Barclays Premier League fixture.

The Easington-born winger joined Middlesbrough as a schoolboy and made his senior debut for the Teessiders when he was 17-years-old in a 2005 Uefa Cup tie.

He went on to play 120 times for Boro before signing for big-spending Manchester City in 2010, the year he won the first of his 12 England caps.

Johnson was part of the City side which dramatically won the 2011-12 Premier League title on the last day of the season.

But he returned to his native North-East that summer, signing a four-year contract with Sunderland in a £10m deal.

Johnson has played 105 league games for the Black Cats over the last three seasons, scoring 20 goals - including three against arch rivals Newcastle United.