Sources told the tabloids the 61-year-old media mogul was startled to see Calvin Mitchell outside the Ed Sullivan Theatre, but she insists stories hinting at the fact he's her son are way off the mark.

Oprah has known Calvin and his family since he was a little boy.

"I met Calvin around the early '90s, I think it was 1992," she tells Entertainment Tonight. "I was doing a film for television called There Are No Children Here. We were shooting in the projects in Chicago and I was sitting on set during a break, and this cute little sparkly-eyed boy came underneath the yellow tape to hand me a soda.

"I was so charmed by him that I started talking to him about his family, his school life, and found out that he was in a situation where his mother didn't have a job and they were stuck in the projects."

Oprah and her partner Stedman Graham became actively involved in Calvin’s life and they helped the youngster and his relatives move out of the projects. She also paid for his education at a boarding school, but ended up being "disappointed" with his life choices, when he declared he wanted to leave his school because the teachers didn't like him.

"I said, 'Calvin, this is the moment. This is a seminal moment for you," Oprah recalls. "I know you are 16 and can't see the road ahead, but if you leave this school and refuse to get an education - I have tried to offer you an education twice - there isn't another school I can put you in. If you leave this school, I am done. There is nothing else I can do'.

"That was my last conversation with Calvin in the early '90s."

That's why she was startled to see him again after taping The Late Show with Stephen Colbert - and she was left broken hearted once again when she realised the street encounter was part of a tabloid set-up.

"I could see the little boy in his eyes, even though time has changed a lot for him, and I said to him, 'What are you doing? Why did you go to the tabloids?'" she adds. "As I left, and he was looking so forlorn, he was like, 'Can I speak to you?' So I said to somebody on my team, 'Will somebody get Calvin's number so I can contact him later?'

"When I realised the whole thing was a set-up, I was no longer interested in speaking to him."