The 41 year-old star – who has an 11 year-old daughter Isan from his first marriage - was thrilled on becoming a father for the second time in 2010 after his partner delivered a baby boy - but his joy was short-lived.
When he developed suspicions about the paternity of the baby, he took a DNA test, which determined he was not the kid's dad.
In his recent UK men’s magazine interview, Elba said: ‘It wasn't immediately obvious - well, it was, because he didn't look like me. But it wasn't immediately obvious what had gone down...
it is just tragic
Talking about the humiliation he felt when he found out the news, he said: ‘To be given that and then have it taken away so harshly was like taking a full-on punch in the face: POW. You know, the truth is, like, even admitting it, I'll probably get laughed at for the rest of my life. But it is just tragic, and it happened.
the worst thing in my life
‘But I wasn't knocked out. I stood right the f**k back up, and I ain't aiming to take another punch in the face ever again. Do you understand what I'm saying? It happened to me. I moved on.’
Until now, the actor has been reluctant to address reports that the baby, named Otenga, by ex-girlfriend Desiree Newberry was not his.
However, the actor explained how he eventually came to terms with the news.
‘I’ve not been an angel in my life, either—do you know what I’m saying? So to a certain extent, what goes around comes around. But for me in the future, I’m about being comfortable. That’s it.’
The actor also used the experience to inspire his hit TV role as DCI John Luther. In the drama, his character is married but separated from his wife - played by the actress Indira Varma – who he hopes to reconcile with, only to find out that she is dating another man.
Not surprisingly, the script touched a nerve. In particular, Elba recalled the moment he was required to film scene in which Luther slams a door during a row with his on screen love interest.
‘And you have to understand, I had just gone through the worst thing in my life with, you know...,’
He explained: ‘Luther came at a time where, you know, it was gaga therapy for me, man. Stupid. I was like, “I’m going in...” And that is what I fking did. I’ll tell you: I did that take, and I remember the room...Indira Varma, the beautiful Indian actress—beautiful girl... The crew were at this end of the room, all packed in. Indira was over there. And I fking let go.
‘Like, all kinds of shit happened in my head. I mean—blitz. Fucked up this door, I mean fked this fking door up. The emotion was going so long after the fking actual scene was ended that everyone sat in silence. Indira was in fking tears; I was in tears.”
‘The camera was still rolling. No one knew what to do. The silence just kept going. And then, finally, someone called, “Cut.”’