Antonio Brown is deflecting responsibility for a sexually-explicit private picture shared on his Snapchat ... claiming his account was hacked.

The ex-NFL superstar broke his silence on the situation Wednesday ... saying he's working with the social media platform to resolve the issue.

As we previously reported, AB's account posted a picture of his ex, Chelsie Kyriss, performing oral sex on him in bed ... and the image was shared all over the Internet.

Chelsie addressed the photo shortly after it went public ... saying she was aware of the post and reported it to Snap.

Chelsie also stated she had previously asked AB to keep their past relationship private ... but he's refused.

A spokesperson for the platform told TMZ Sports AB's account was suspended and an investigation was underway, citing Community Guidelines that "prohibit sexually explicit content and bullying or harassment of any kind."

Given AB's previous Snap activity -- including posting fake nude images of Gisele Bundchen -- it's entirely possible he is attempting to cover his ass ... considering almost all states have laws on the books to punish people who post revenge porn.

But, if his account was seriously hacked, it's a truly unfortunate situation for everyone involved.