The Sunderland player was suspended by the Premier League club on Monday, after Durham Police confirmed that a 27-year-old man had been taken into custody.
A statement from Durham Police on Tuesday said: "A 27-year-old man arrested on suspicion of sexual activity with a girl under 16 years has been released on police bail pending on-going investigations."
Johnson made the switch to Sunderland from City in 2012, having won the Premier League and FA Cup during his time time at the Etihad Stadium.
The former Middlesbrough player has earned 12 international caps with England, scoring two goals in Euro 2012 qualifying victories against Bulgaria and Switzerland.
Johnson's suspension means he will not be part of Sunderland's travelling party for the clash at Hull City on Tuesday.
