Charlize Theron has reportedly adopted a second child.

The 39-year-old actress has gained custody of a girl named August who is ''an African-American girl'' who was ''born in the United States'' according to gossip website TMZ.

The 'Mad Max: Fury Road' star took custody of the tot last month following a six-month adoption process, specifically requesting a girl after adopting her son Jackson from South Africa in 2012.

Charlize - who will celebrate her 40th birthday this week - currently lives in Los Angeles with her three-year-old son.

Back in May, the blonde beauty admitted she was ''open'' to having more children, but gave no hints she was planning on adopting again.

Asked if she would like more kids, she said: ''Yeah. I mean, I'm so open to anything in my life. I was never like, 'Oh god no just one.' I was always kind of open to whatever kind of happens.''

However, the new arrival comes just weeks after she split up with fellow actor Sean Penn who she had been dating since early 2014, with pals revealing the relationship ''ended abruptly.

A source said: ''As far as I know, Charlize won't talk to him. She just cut if off. They're absolutely done.

''[It] was very volatile. They both have intense personalities and are control freaks. He's a tough person, and she's no picnic either.''

Another source said: ''It ended abruptly. If you get on her bad side, she finds it hard to forgive.''