The famously-private actor initially let slip the news of his impending fatherhood in September (16), when he appeared at a panel chat about his hit Marvel TV show at the Toronto Fan Expo in Canada.

At the event, Cox revealed his partner will give birth "very soon", and joked, "In fact, my girlfriend was pretty amused when I said I was going to Toronto a couple weeks beforehand, by the way. So, keep your legs closed."

Now E! News reports Cox and his partner, who has been identified as Samantha Thomas, a producer on Marvel shows Agents of S.H.I.E.L.D. and Jessica Jones, have officially become parents.

No specific details about the baby's birth have been revealed, but Cox confirmed the tot's arrival in a recent live chat on Marvel's Facebook page with Luke Cage star Mike Colter.

During the appearance, Colter congratulated the "proud new dad", to which a smiling Cox replied, "I haven't finished (watching) your show yet, but you know I have a reason."

And Cox and Thomas are said to have double the reason to celebrate amid speculation they have also secretly married.