An Arkansas judge has confessed to leaking confidential information about Charlize Theron adopting her son months before she made an official announcement.

The Oscar winner became a mom to Jackson in early 2012 and managed to keep the news secret for several weeks.

She eventually confirmed she had adopted in March of that year (12), but the news had been leaked on a Louisiana State University message board two months earlier (Jan12).

A poster using the name 'geauxjudge' revealed the star was going through adoption proceedings and that she had turned up in court in a "long brown wig (and) oversized clothes" to "camouflage her appearance".

After a online report pointed the finger at Circuit Judge Mike Maggio on Monday (03Mar14), he has admitted being behind the leak.

A statement from Maggio reads, "I take full responsibility for the comments that have been attributed to me.

"I apologize deeply for my lapse in personal judgment and for that, I have no excuse. The comments posted were not acceptable. These comments are not a reflection of who I am."

Maggio has now ended his campaign for a seat on the Arkansas Court of Appeals. The state's Judicial Discipline and Disability Commission director David Sachar has ordered an investigation into the scandal.