The black and white photo, which appeared on social media two weeks ago and has now been taken down, shows former Hannah Montana star Moises slouched on a bed shirtless, while Willow lies clothed in front of him.
Now it’s been reported that the Los Angeles Department of Children And Family Services has launched a probe.
RadarOnline claims the investigation was launched last week and that Will, 45, and 42-year-old Jada have been 'extremely cooperative’.
A source told the website: “Social workers will also be talking separately with Willow, and they also want to talk to the young man in the picture with her as well.
“This won’t just be one or two visits with the family, and it will likely be an open investigation for at least a month, out of an abundance of caution.”
Will and Jada have not made any comment about an investigation. But when asked about the photo, Jada lashed out as she arrived at Los Angeles Internation Airport on 7 May.
Speaking in a video on TMZ she said: “Here's the deal. There was nothing sexual about that picture of that situation. You guys are projecting your trash onto it … and your acting like covert paedophiles and that's not cool.”
On the same day Willow's brother Jaden Smith, 15, made a show of solidarity to his sister when he was spotted out and about with Moises.